PITTSBURGH — The Pittsburgh Pirates' bullpen had been automatic with late-inning leads. Until Saturday night.
Jason Castro led off the 11th inning with a double and scored the go-ahead run on a close play at the plate as the Houston Astros topped the Pirates 4-2.
Castro doubled off the top of the center-field fence against rookie reliever Bryan Morris (1-2), and Carlos Pena was intentionally walked one out later. The runners moved up on a wild pitch and Castro scored when he beat second baseman Neil Walker's throw home on Matt Dominguez's fielder's choice grounder.
Pittsburgh manager Clint Hurdle argued the call with plate umpire C.B. Bucknor and was ejected. Pinch-hitter J.D. Martinez followed with an RBI single to make it 4-2.
"I thought he was out, but I watched the replay and I was wrong. C.B. got the call right," Hurdle said. "(Castro) made a good slide."
The Pirates had been 18-0 this season when leading after seven innings but suffered their first loss partially because Chris Carter's run-scoring single in the eighth inning tied the game at 2 and ended setup reliever Mark Melancon's string of 13 consecutive scoreless relief appearances, covering 13 innings.
Melancon has a 0.82 ERA, allowing just two runs in 22 games and 22 innings.
"The guy has been pitching great and he pitched great again tonight," Hurdle said. "A broken-bat single and the lead is gone. It's a tough game. You can do the right thing and it can still turn out wrong. Mark made a good pitch and gave up the tying single."
Rookie Jose Cisnero (1-0) struck out five in 3 2-3 scoreless relief innings for his first major league win. Jose Veras pitched a scoreless 11th for his sixth save as Houston (12-31) won for the second time in three games since losing six in a row.
Houston's Jose Altuve had three hits to raise his batting average to .342 after being activated from the bereavement list before the game. Altuve missed three games after his grandmother died in his native Venezuela.
Andrew McCutchen hit two doubles and Brandon Inge had two hits for Pittsburgh, which lost for the second time in nine games.
Pittsburgh starter A.J. Burnett held Houston to one run in seven innings while allowing five hits and four walks, but wound up with a no-decision when Melancon could not hold the lead. Burnett struck out seven to raise his National League-leading total to 79. He has not allowed more than three earned runs in any of his 10 starts this season.
"You can talk about (the Astros') record, but they're all big leaguers, they're all up here for a reason," Burnett said. "They battled me. They had some really good swings with two strikes and they fought off some tough pitches. I felt good to get out of it with only one run allowed."
The Astros' Erik Bedard gave up two runs and seven hits in six innings with three strikeouts and no walks in his first career start against Pittsburgh. The veteran left-hander was the Pirates' opening day starter last season, but was released on Aug. 30 after going 7-14.
"You don't really think about who it's against," Bedard said. "You just want to win the ballgame."
Inge put Pittsburgh in front 2-1 in the sixth when he hit a two-out RBI single to left field off Bedard.
The Pirates scored the game's first run on consecutive doubles by McCutchen and Gaby Sanchez with two outs in the first inning.
Houston tied in the fifth on Altuve's two-out RBI single.
NOTES: Pirates RHP Jeff Karstens (right shoulder inflammation) allowed two unearned runs in four innings Saturday night for Double-A Altoona in a rehab start at Richmond in the Eastern League. ... Pittsburgh RHP James McDonald, who was placed on the disabled list retroactive to May 1 with shoulder inflammation, played long toss Saturday. The next step is for him to throw off a mound Tuesday before the Pirates can begin to think about determining a timetable for his return. . The three-game series concludes Sunday with Houston RHP Lucas Harrell (3-4, 5.11) pitching against LHP Jeff Locke (3-1, 3.15).