LONDON — Britain, Ireland and the revitalized American team are all off to a perfect start in the Olympic boxing tournament.

Jose Ramirez and Errol Spence won their opening bouts Sunday night to improve the Americans to 4-0, while Freddie Evans and Josh Taylor rode the home crowd's raucous cheers to a 3-0 start for Britain. Welterweight Adam Nolan then added a win in the late session, pushing Ireland's record to 3-0.

Welterweight Custio Clayton also notched Canada's first Olympic win in eight years on an eventful day at ExCel.

The young Americans fought nearly back-to-back, and both produced impressive wins over seasoned amateur veterans for a formerly powerful boxing nation that won just six total fights and one medal during its worst Olympic performance in Beijing.

This tight-knit American team doesn't plan to go out that way.

"I'm not surprised, because we worked very hard in training camp," Spence said of the American team, which didn't have a coaching staff until four weeks before the Olympics began. "Everybody has a certain plan, and we're all following that plan. We're all relaxed and focusing on the task at hand."

Ramirez, a 19-year-old business major at Fresno State and a former Starbucks barista, pressed the action and fought out of trouble throughout a 21-20 win over France's Rachid Azzedine. Ramirez got a last-minute pep talk from his family on Skype, saying, "I'm glad this place has WiFi."

"There's always a lot of nerves when you have a lot of intensity when you go in there with a lot of motivation," said Ramirez, who sported neon-yellow boots. "I feel like I shook those nerves out. ... I didn't really feel a strong hit from him. I just stayed smart, fought hard and continued to work."

Spence had an easier time in a rougher fight, persevering through questionable tactics by three-time Brazilian Olympian Myke Ribeiro de Carvalho for a 16-10 victory. The national champion welterweight has a tough second-round matchup against third-seeded Krishan Vikus of India.

"The first one is always the toughest one, because you've got the butterflies, and I haven't fought since, like, March," Spence said.

The Brits are on a roll, too.

After Evans posted an 18-10 victory over Algerian welterweight Ilyas Abbadi in the final bout of the afternoon session, Taylor upset Brazilian lightweight Robson Conceicao 13-9 in the opening bout of the evening session, delighting two sold-out crowds waving dozens of Union Jacks and giving repeated standing ovations.

The crowd support clearly is buoying Britain, which has thoroughly revitalized its amateur ranks in the eight years since teenager Amir Khan won a silver medal in Athens as the team's lone fighter, and this strong start at home suggests podium finishes in the Brits' future.

"It was unbelievable, like nothing I've ever experienced before," Evans said of the crowd support after he peppered Abbadi with quick punches. "It just builds you up and gives you a great positive feeling."

Taylor jumped to a lead in the first two rounds and fought defensively in the third, barely hanging on for the win against the promising Conceicao, who nearly upset top-ranked Vasyl Lomachenko in last year's world championships.

Taylor and Conceicao sparred in the British training camp during the weeks leading up to the Olympics.

"But I was just covering up, because I didn't want to show him too much just in case I drew him," Taylor said. "I never expected to draw him, though. ... It's the best I've ever felt in my life."

Clayton earned a 12-8 decision over Mexico's Oscar Molina, while France's Alexis Vastine beat German welterweight Patrick Wojcicki 16-12 in the most entertaining early fights.

Dominican lightweight Wellington Arias was impressive in a 17-8 victory over Colombia's Eduar Marriaga, but earned the dubious honor of facing Ukraine's Lomachenko on Thursday.

Clayton, a 24-year-old welterweight, is from Dartmouth, Nova Scotia, just across the Bedford Basin from Halifax. With elusive movement and timely punching, Clayton avenged a loss at the 2010 Pan-American championships to Molina, the brother of 2008 U.S. Olympian Javier Molina.

"I think I did amazing," said Clayton, who hoped his daughter, Cheyla, was watching at home. "All the hard work has paid off. I had a tough draw, I thought, but I've fought him before. It was all a learning experience. I sat down and saw what I did, and then what I should do."

Canada hasn't won an Olympic boxing medal since 1996, and no golds since Lennox Lewis' super heavyweight win in Seoul in 1988.

Loading Slideshow...
  • Olympic Boxing Day 2

    USA's Jose Ramirez makes his way to a fight against France's Rachid Azzedine before a lightweight 60-kg preliminary boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    France's Rachid Azzedine, left, fights USA's Jose Ramirezin their men's light 60-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    France's Rachid Azzedine and USA's Jose Ramirez fight in a men's light 60-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    USA's Jose Ramirezin reacts as he defeats France's Rachid Azzedineafter a men's light 60-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    China's Liu Qiang, and Australia's Luke Jackson, fight during their men's light 60-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    India's Bhagwan Jai, right, connects with Andrique Allisop of the Seychelles, during men's light 60-kg boxing at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    France's Alexis Vastine, right, lands a punch against Germany's Patrick Wojcicki, during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Great Britain's Freddie Evans, and Algeria's Ilyas Abbadi, fight during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Great Britain's Freddie Evans, left, and Algeria's Ilyas Abbadi, fight during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Nigeria's Moustapha Abdoulaye, right, connects against Australia's Cameron Hammond, during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Canada's Custio Clayton, right, punches Mexico's Oscar Molina, during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Canada's Custio Clayton, reacts with fans after beating Mexico's Oscar Molina, at their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Great Britain's Josh Taylor reacts after defeating Brazil's Robson Conceicao during a lightweight 60-kg preliminary boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Lithuania's Evaldas Petrauskas, left, fights Hungary's Miklos Varga in their men's light 60-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Lithuania's Evaldas Petrauskas, right, fights Hungary's Miklos Varga in their men's light 60-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Algeria's Abdelkader Chadi, left, fights Turkey's Fatih Keles during their men's light 60-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Algeria's Abdelkader Chadi walks away after losing to Turkey's Fatih Keles in a lightweight 60-kg preliminary boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    USA's Errol Spence fights Brazil's Myke Ribeiro de Carvalho during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    USA's Errol Spence fights Brazil's Myke Ribeiro de Carvalho during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Ecuador's Carlos Sanchez Estacio fights Ireland's Adam Nolan, left, during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Ireland's Adam Nolan reacts after defeating Ecuador's Carlos Sanchez Estacio during their men's welter 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    China's Mai Maitituersun Qiong fights Russia's Andrey Zamkovoy in a men's welterweight 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Iraq's Ahmed Abdulkareem Ahmed, right, fights South Africa's Siphiwe Lusizi,during their men's welterweight 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.

  • Olympic Boxing Day 2

    Iraq's Ahmed Abdulkareem Ahmed walks away from the ring after losing to South Africa's Siphiwe Lusizi after a men's welterweight 69-kg boxing match at the 2012 Summer Olympics, Sunday, July 29, 2012, in London.