LONDON >> Claressa Shields ducked one punch, deftly leaned away from another, and stuck her tongue out at her Russian opponent. Just an American teenager having a little fun.

After all, Nadezda Torlopova is nearly twice Shields’ age and about half her speed. And Shields had to laugh at any boxer trying to get between her and a historic Olympic gold medal.

The 17-year-old middleweight from Flint, Mich., beat Torlopova 19-12 today, capping her rapid ascent through women’s boxing with a title in its Olympic debut.

“This was something I wanted for a long time, even when boxing wasn’t going all right, even when my life wasn’t going all right,” said Shields, who found sanctuary in a boxing gym during a rough childhood.

“All I wanted was a gold medal, and I kept working towards it, even when people were saying I couldn’t do it. I’m too young. I couldn’t do it. There were girls who were going to beat me because of better experience, more experience. I proved them all wrong.”

Shields did it in style — shuffle-stepping, brawling and even winning over a crowd that showed up to cheer Irish lightweight Katie Taylor and British flyweight Nicola Adams, who also won gold medals.

Shields had her hand over her heart on the medal podium when she abruptly burst into laughter, her head snapping back almost as if she had just been punched in the face.

That’s a feeling her opponents in the first Olympic women’s boxing tournament know quite well.

Only they’re not laughing.

“I’m surprised I didn’t cry,” Shields said. “I was sweating, though.”

Shields, Taylor and Adams triumphed in rapid succession on the final day of the London Games’ landmark tournament, claiming the first Olympic titles in a growing sport that was banned in Britain until 1996.

The five-day event was one of London’s biggest hits. And even amid the sea of Irish fans cheering Taylor’s every move, Shields was one of the breakout stars of the games. An ugly Olympics for the U.S. team ended with a performance worthy of Cassius Clay, Joe Frazier, Oscar De La Hoya and every American Olympic champion that came before Shields.

Shields found her purpose with coach Jason Crutchfield at Berston Field House in Flint after her father — who spent seven years of Claressa’s childhood in prison — infused her with a passion for boxing. Shields has turned into a polished athlete with a wild streak in the ring.

Even the 33-year-old Torlopova had to applaud the ascent of her division’s new ruler.

“She’s young, after all, and she’s quicker,” Torlopova said. “It happens that speed overcame experience. Something was lacking, most probably speed. After the second round, when they announced I was two points down, I knew that was it. … You have to know how to lose. She’s a worthy opponent. Good job.”

Shields capped her rise through the amateur ranks in the past two years with three strong performances in the London ring, providing USA Boxing with a much-needed boost. Shields won the 12-member American team’s only gold medal in London, and flyweight Marlen Esparza took a bronze, but the winningest nation in Olympic boxing history got no medals from its men’s team for the first time.

“I don’t think anybody would feel bad about me representing them,” Shields said. “I think I did a pretty good job.”

Most of the raucous crowd came to see Taylor, who won Ireland’s first gold medal at these Olympics amid a patriotic fervor of Irish flags, songs and thousands of devoted fans who treat her as a sports icon at home.

Taylor’s victory, a 10-8 win over Russia’s Sofya Ochigava, was perhaps the least memorable part of the afternoon. She barely beat Ochigava in a defensive fight, relying on a 4-1 points swing in the third round after trailing midway through the bout.

Unlike most of Taylor’s fights, the result was still in doubt when the judges’ scores were announced. Taylor fell to her knees and looked skyward when her arm was raised, bringing an even louder roar from the fans, many of them in green face paint and elaborate Irish-themed costumes.

Taylor took a victory lap of ExCel arena after the medal ceremony, trailing a green, white and orange Irish flag behind her.

“It’s been the dream of my life,” said Taylor, a four-time world champion. “The support was incredible. I was a bit shaky during the fight. She is a great boxer.”

Ochigava predicted Wednesday she would lose a close fight to the arena favorite, and Taylor’s longtime foil wore an exasperated look of disbelief after the final scores were announced. She accepted her silver medal with arms folded across her chest, refusing to acknowledge the crowd’s cheers — but she hugged Taylor when all the medalists posed for photos later.

“It was difficult to fight when everything is against you,” Ochigava said. “There’s a lot of support for Katie, but I imagined that all of them are supporting me. I wanted to get the gold. It seemed I could do almost anything, but it wasn’t enough.”

Taylor is the unofficial pound-for-pound champion of women’s boxing after winning her world titles with an entertaining style. Ochigava is Taylor’s only rival for lightweight supremacy, and the Russian criticized Taylor on Wednesday after both fighters won semifinal bouts, saying her Irish foe gets star treatment from referees and judges.

Try telling that to the crowd that embraced Taylor with unmatched fervor, realizing the Irish team’s flag-bearer was their best hope for gold in London. Taylor eventually teared up as she left the ring in her robe, but got it together for the medal ceremony, taking another victory lap around the arena with the flag trailing behind her.

Adams got nearly as much love for a victory that was perhaps even more impressive. She stunned world champion Ren Cancan of China in a 16-7 win that was met with cheers from a crowd that included the Duchess of Cambridge, formerly known as Kate Middleton.

Adams knocked down Ren — a rare occurrence in such a high-level amateur fight — in the second round with a left to the throat and a right to the head. She eventually finished off the top-seeded flyweight, dominating the middle rounds by a combined 10-3.

Adams celebrated the final bell by throwing a few punches at the roaring home crowd. Adams’ two British teammates also were favored to medal, but lost early.

“I am so happy and overwhelmed with joy right now,” Adams said. “I have wanted this all my life, and I have done it.”