MIAMI — LeBron James better get well fast. He's about to play for a championship.

Hardly able to move, James returned from a left leg injury to make the tiebreaking 3-pointer with 2:54 remaining and the Miami Heat held off Russell Westbrook and the Oklahoma City Thunder for a 104-98 victory on Tuesday night and a 3-1 lead in the NBA Finals.

With James watching the final moments, Mario Chalmers finished off a stellar 25-point effort that matched Dwyane Wade. James had 26 points, 12 assists and nine rebounds, only missing a triple-double because he was on the bench at the end after hurting his leg with a fall to the court.

Game 5 is Thursday night and James will have a chance to finish a championship chase that started in Cleveland before he famously -- or infamously -- left for South Florida. No team has blown a 3-1 lead in the finals.

Westbrook scored 43 points for the Thunder, who wasted an early 17-point lead but were never out of the game because of their sensational point guard. Kevin Durant had 28 points but James Harden threw in another clunker, finishing with eight points on 2-of-10 shooting. Westbrook and Durant were the only Thunder players to score in the last 16:46.

James stumbled to the court on a drive midway through the fourth quarter, staying on the offensive end of the floor as the Heat regained possession on a blocked shot, and he made a short jumper that made it 92-90. After Westbrook missed a jumper, the Heat called timeout as James gingerly went to the court. Unable to walk off, he was carried to the sideline by a pair of teammates.

He returned to a huge roar with a little over 4 minutes left, and after Chris Bosh tied it, James slowly walked into a pull-up 3-point attempt – perhaps doing so knowing he couldn't drive by anyone.

That made it 97-94, and when Wade followed with a layup with 2:19 left, the Heat finally enough room to withstand Westbrook, who kept coming all night.

"Whatever it takes. No excuses," Wade said. "You don't want to leave this arena saying you missed opportunities."

Chalmers sure didn't. The player who was struggling so badly that the Thunder put Durant on him in hopes of avoiding further foul trouble made 9 of 15 shots, scoring more points than he had in the previous three games.

"Mario Chalmers is a winner," Wade added. "He's due for a big game and he came through for us."

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  • Oklahoma City Thunder v Miami Heat - Game Four

    A fan of the former NBA franchise Seattle SuperSonics which moved and became the Oklahoma City Thunder shows support for the Miami Heat to beat the Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Alberto Shamosh, left of Mexico, and Tyrone Jackson of Miami show their support for the Miami Heat before Game 4 of the NBA Finals basketball series against the Oklahoma City Thunder, Tuesday, June 19, 2012, in Miami. (AP Photo/Lynne Sladky)

  • Oklahoma City Thunder v Miami Heat - Game Four

    LeBron James #6 of the Miami Heat looks on during warm ups against the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida

  • Oklahoma City Thunder v Miami Heat - Game Four

    LeBron James #6 of the Miami Heat defends in the first quarter against Kevin Durant #35 of the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Kendrick Perkins #5 of the Oklahoma City Thunder posts up in the first quarter against Shane Battier #31 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Dwyane Wade #3 of the Miami Heat is helped up by teammate Shane Battier #31 in the first quarter against the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Chris Bosh #1 of the Miami Heat drives for a shot attempt in the first quarter against Nick Collison #4 of the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Russell Westbrook #0 of the Oklahoma City Thunder drives for a shot attempt in the first quarter against Dwyane Wade #3 and Shane Battier #31 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Serge Ibaka #9 of the Oklahoma City Thunder looks on prior to playing against the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Dwyane Wade #3 of the Miami Heat gestures towards the fans prior to playing against the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Nick Collison #4 and Kevin Durant #35 of the Oklahoma City Thunder fight for rebound position in the first half against Shane Battier #31 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Kevin Durant #35 of the Oklahoma City Thunder drives for a shot attempt in the first half against Udonis Haslem #40 and Shane Battier #31 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    James Harden #13 of the Oklahoma City Thunder drives in the first half against Shane Battier #31 and Mike Miller #13 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Dwyane Wade #3 of the Miami Heat grabs his back as he lies on the court in pain in the second quarter against the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Chris Bosh #1 of the Miami Heat reacts in the second quarter against the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Chris Bosh #1 of the Miami Heat attempts a shot in the first half against Thabo Sefolosha #2 of the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    LeBron James #6 of the Miami Heat drives in the first half against Kendrick Perkins #5 of the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    LeBron James #6 of the Miami Heat drives against James Harden #13 of the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Serge Ibaka of the Oklahoma City Thunder and Dwyane Wade of the Miami Heat grapple for the ball during Game Four of the NBA Finals on June 19, 2012 at the American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    LeBron James of the Miami Heat is guarded by Russell Westbrook (R) of the Oklahoma City Thunder during Game Four of the NBA Finals on June 19, 2012 at the American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    James Harden of the Oklahoma City Thunder shoots against the Miami Heat during Game Four of the NBA Finals on June 19, 2012 at the American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    LeBron James #6 of the Miami Heat drives for a shot attempt in the second half against Thabo Sefolosha #2 of the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    James Harden #13 of the Oklahoma City Thunder defends against Dwyane Wade #3 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Kevin Durant #35 of the Oklahoma City Thunder attempts a shot against Chris Bosh #1 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Kevin Durant of the Oklahoma City Thunder takes a tumble against the Miami Heat during Game Four of the NBA Finals on June 19, 2012 at the American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Kevin Durant #35 of the Oklahoma City Thunder attempts a shot in the first half against Shane Battier #31 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Dwyane Wade #3 of the Miami Heat attempts to block a shot attempt in the first half against Russell Westbrook #0 of the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Russell Westbrook #0 of the Oklahoma City Thunder misses a dunk attempt in the first half against Chris Bosh #1 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Russell Westbrook #0 of the Oklahoma City Thunder attempts a shot in the seocnd half against James Jones #22 of the Miami Heat in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida.

  • Dwyane Wade of the Miami Heat scores dur

    Dwyane Wade of the Miami Heat scores during Game Four of the NBA Finals against the Oklahoma City Thunder on June 19, 2012 at the American Airlines Arena in Miami, Florida. AFP PHOTO / DON EMMERT (Photo credit should read DON EMMERT/AFP/GettyImages)

  • Tyrone Jackson of Miami shows his support for the Miami Heat before Game 4 of the NBA finals basketball series against the Oklahoma City Thunder, Tuesday, June 19, 2012, in Miami. (AP Photo/Lynne Sladky)

  • The Heat Street Band performs outside the American Airlines Arena before Game 4 of the NBA Finals basketball series, Tuesday, June 19, 2012, in Miami. (AP Photo/Lynne Sladky)

  • Oklahoma City Thunder v Miami Heat - Game Four

    MIAMI, FL - JUNE 19: A fan of the Miami Heat shows support for the Heat against prior to playing against the Oklahoma City Thunder in Game Four of the 2012 NBA Finals on June 19, 2012 at American Airlines Arena in Miami, Florida. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and or using this photograph, User is consenting to the terms and conditions of the Getty Images License Agreement. (Photo by Ronald Martinez/Getty Images)

  • Oklahoma City Thunder v Miami Heat - Game Four

    Russell Westbrook (R) of the Oklahoma City Thunder tries to navigate under pressure from Mario Chalmers (L) and Shane Battier (C) the Miami Heat during Game Four of the NBA Finals on June 19, 2012 at the American Airlines Arena in Miami, Florida.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Miami Heat small forward LeBron James (6) stays down after taking a spill against the Oklahoma City Thunder during the second half at Game 4 of the NBA Finals basketball series, Tuesday, June 19, 2012, in Miami.

  • Oklahoma City Thunder v Miami Heat - Game Four

    Miami Heat small forward LeBron James (6) is carried from the floor after taking a spill against the Oklahoma City Thunder during the second half at Game 4 of the NBA Finals basketball series, Tuesday, June 19, 2012, in Miami.

  • Oklahoma City Thunder v Miami Heat - Game Four

    After taking a fall against the Oklahoma City Thunder, Miami Heat small forward LeBron James (6) sits on the sideline during the second half at Game 4 of the NBA Finals basketball series, Tuesday, June 19, 2012, in Miami.