ADELAIDE, Australia — U.S. striker Josh Wolff reckons he rides his luck in soccer like he does at poker and roulette.

His celebration in the left corner after bringing the United States to 1-1 in their Olympic soccer quarterfinal against Japan on Saturday reflected his penchant to try his hand at the luck of the draw.

Sprinting into the corner, he dropped to the ground and pretended to throw dice and deal cards, later explaining that he hadn't been near a casino Down Under but was feeling lucky.

The feeling proved accurate. Wolff earned a last-minute penalty kick, which Pete Vagenas put home, to tie it 2-2 and send the game into overtime. U.S. substitute Sasha Victorine blasted a penalty kick just past the desperate dive of goalkeeper Seigo Narazaki for a 5-4 shootout victory.

The U.S. men, who'd never before advanced out of the first round at an Olympic tournament, now play Tuesday in Sydney in a semifinal against Spain, a 1-0 winner over Italy in another quarterfinal.

"Me, I'm just excited about going to Sydney to be a part of the Olympics," said the 23-year-old striker. "It's going to be pretty wild. We're going for a medal and it's going to be exciting."

The Americans finished atop Group C, surprising the Czech Republic 2-2 and Cameroon 1-1 before beating Kuwait 3-1.

They've played two games in Canberra and one each in Melbourne and Adelaide, but have been desperate to get to Sydney, the Olympic city, and soak up some of the atmosphere.

Some of the players had already booked flights home Sunday to rejoin their MLS teams for playoffs games, but now the 18-man squad travels Sunday to prepare for a shot at the medals.

"Nobody really expected us to be here," coach Clive Charles said. "I've been to World Cup games and qualifiers but I've never been involved in anything as wonderful as this.

"It had everything — the guys were phenomenal. It's great to be in a competition of this magnitude and be involved when a lot of the class teams haven't made it this far. It says a lot about American soccer."

Wolff scored the United States' first goal and earned a last-minute penalty kick, which Pete Vagenas put home.

The Chicago Fire forward then took the critical fourth kick in the shootout after Japan missed its fourth, giving the United States an edge for the first time.

Substitute Victorine moved in and nailed the winner, to the utter disbelief of the Japanese.

Victorine, who replaced Chris Albright in extra time and then kicked the fifth penalty just past Narazaki's dive, said the game was the greatest of his career.

"Coming off the bench into a situation like that is amazing," Victorine said.