Carli Lloyd scored early in both halves, Hope Solo made a lunging late save as the Japanese pushed frantically for a tying goal, and the entire roster found the redemption it had been seeking since that penalty kick shootout loss in Germany last year.
"We came so close to winning the World Cup," Wambach said. "We knew if we put our energy and belief in each other into this year, we could pull off something special."
Before 80,203 fans at Wembley Stadium, an Olympic record for a women's soccer game, the teams put on a back-and-forth, don't-turn-your-head soccer showcase, proving again that these are the two premier teams in the world. Women's soccer is still in its formative stages in Britain, but the match proved more than worthy for the hallowed grounds of the beautiful game.
Back home, America was paying attention -- just as it was last year and despite all the other Olympic events. Even President Barack Obama, while visiting the U.S. Olympic Committee's training center in Colorado Springs, Colo., offered a "special shout-out" to the women's team for its victory.
"Congrats to the U.S. women's soccer team for a third straight Olympic gold. So proud," the President posted on Twitter.
At the final whistle, there was a group-hug celebration that unleashed a year of bottled-up frustration. Many of the players paraded with the flag and put on the celebratory T-shirts.
Solo was at center of the biggest scrum, fitting for a player who was so crucial to the victory. The goalie gets a lot of flak for her off-field pursuits -- including "Dancing With the Stars" and her candid comments on Twitter -- but she made several plays Thursday that showed again that she's the best in the world at what she does.
"Hope Solo, she says a lot on Twitter, I guess. I don't follow her," U.S. coach Pia Sundhage said. "But what matters is what kind of team player she is and how she performs. ... Today Hope Solo had a very good game. She brought the gold back to the United States of America."
Wambach, the outspoken co-captain who missed the Beijing Games with a broken leg, was always the player most impassioned about the mission to get the Americans back atop the podium. She had spoken of "nightmares" from the Japan defeat, and now they've been replaced by tears of happiness.
The loudest cheers erupted when she received her gold medal, and she was the only one to get a hug from American IOC member Angela Ruggiero, who put the medal around Wambach's neck.
"The Olympics is a perfect platform in terms of what life is," Wambach said. "You cannot win at everything you attempt in life. You have to be willing to fail and fall flat on your face in order to get glory. And we really did fail last year, in our opinion. We have to give Japan credit. They're a fantastic team.
"But anything less than winning for us is a failure. And we worked tirelessly all year long to prove that we still can win and we are still champions."
The U.S. team has won four of the five Olympic titles since women's soccer was introduced at the 1996 Atlanta Games, taking second place at the 2000 Games in Sydney.
Settling for silver, the Japanese players huddled together in defeat, with coach Norio Sasaki trying to encourage them. Karina Maruyama was inconsolable. Aya Miyama bowed her head and Asuna Tanaka wiped away tears.
But they were all smiles when they re-emerged for the medal ceremony, bouncing their way to the podium.
"Even though we got defeated and we couldn't win in this Olympics, if I look at it objectively, they all played very well," Sasaki said through a translator. "There is nothing we should be ashamed of."
Lloyd also scored the winning goal in the gold medal match against Brazil in Beijing four years ago.
On Thursday she found the net in the eighth and 54th minutes, making it four goals in the tournament for the midfielder who lost her long-held starting job weeks before the Olympics. She got back on the field when Shannon Boxx injured her hamstring in the opener against France and started every game since.
"I think I just come up big in big moments. That's what I've trained for," Lloyd said. "I worked my butt off day-in and day-out. I don't think there's anybody that works harder than I do. I was on a mission this Olympics to prove everybody wrong, and that's what I did. To show everybody that I belong on the field."
Yuki Ogimi answered in the 63rd minute, and Mana Iwabuchi nearly had the equalizer in the 83rd -- stripping the ball from captain Christie Rampone and swooping in alone against Solo -- only to be thwarted when the goalie flung her entire body to the left to push the shot away.
"I knew I had to make the save," Solo said. "That was pretty much my only thought. I had to make that save."
Throughout the game, Japan perhaps played just as beautifully as the Americans, using speed and discipline to dominate possession and scoring chances for long stretches. The Japanese were unfortunate not to have a penalty kick awarded in the first half for a clear hand ball by U.S. midfielder Tobin Heath, who stuck out her left arm to stop a free kick inside the area.
The Americans knew they'd gotten away with something.
"The one on Tobin?" Rapinoe said, smiling. "Thank God I'm not a referee."
Asked about the play, Japan coach Sasaki responded with a wry grin and said he wondered what the referee was thinking at the time. He diplomatically added that he respected the call.
Japan also had two shots hit the crossbar, one off the left hand of a leaping Solo, who was kept constantly busy for the first time this tournament. The closest the U.S. came to doubling the lead in the first 45 minutes came when Azusa Iwashimizu attempted to clear a routine ball played in front of the net -- and headed it off the post.
Lloyd's first goal began with a run by Heath down the left side. She fed Alex Morgan, who settled the ball near the goal line, spun and chipped it toward Wambach. Wambach raised her left foot for the shot, but Lloyd charged in and got to it first, her strong running header beating goalkeeper Miho Fukumoto from 6 yards out.
Lloyd extended the lead with a 20-yard right-footer just inside the left post after a run from midfield through the heart of the Japanese defense.
Ogimi soon cut the deficit to one after a mad scramble in front of the net. Rampone saved a shot off the line, but the ball went to Homare Sawa, who fed Ogimi for the tap-in.
Another scramble followed after U.S. defender Amy LePeilbet saved yet another shot off the line in the 74th minute, but this time her teammates were able to corral the ball before a Japanese player could pounce on it.
Boxx was back in the starting lineup after the missing four games with the hamstring injury. Lauren Cheney, who injured an ankle in the semifinals, began the game on the bench for the first time this tournament.
Canada won the bronze earlier Thursday, beating France 1-0 at Coventry.
The previous record crowd for a women's soccer game at the Olympics was 76,481 at the Atlanta Olympics. That game was played at Athens, Ga., which isn't quite Wembley.
"I reminded myself that I was at Wembley, and it is a final, and the players got the gold," the Swedish-born Sundhage said. "It's happiness. It's hard to explain in English. It's hard to explain in Swedish, anyway. Just the fact that you're standing in the middle of something huge."
Information from The Associated Press was used in this report.
