updated 11:14 p.m. ET July 18, 2009

PHILADELPHIA - Worn down and undermanned, the United States found a way to rally.

Now the Americans remain in position to win their third straight CONCACAF Gold Cup.

Kenny Cooper converted a penalty kick in the 105th minute, giving the two-time defending champions a 2-1 victory over Panama and a semifinal berth against Honduras, which beat Canada 1-0 in the opener of Saturday’s doubleheader.

With just one regular in the starting lineup and down a goal early, U.S. coach Bob Bradley told his team at the first break it was time to get going and play like defending champions.

“Bob told us, ‘All right, we’re in a tough one,”’ midfielder Kyle Beckerman said. “He told everybody to step up and play better, and we’ll get our chances.”

They made the most of them the rest of the way.

“It was ideal to finish it off in regulation, but it took 30 extra minutes and that still says something about this group,” Bradley said.

Blas Perez put Panama ahead in first-half stoppage time, but Beckerman tied the score in the 49th.

In Sunday’s quarterfinal doubleheader, Guadeloupe meets Costa Rica and Mexico faces Haiti in the first sporting event at the Dallas Cowboys new stadium at Arlington, Texas. The semifinals are Thursday in Chicago.

“It’s going to be another tough one,” Beckerman said. “This definitely took a lot out of us.”

Cooper was kicked in the gut by Panama’s Roman Torres as they went for the ball, and the penalty was awarded by Mexican referee Benito Archundia, who also worked Italy’s victory over Germany in the 2006 World Cup semifinal. Goalkeeper Jaime Penedo correctly dived to his right, but Cooper’s low kick went in off the post.

Panama’s Felipe Baloy received a his second yellow card, and a red, for arguing with Archundia following the final whistle.

The Americans, who beat Honduras 2-0 in the first round, have not lost at home to an opponent from the North and Central American and Caribbean region since a 3-2 defeat to the Catrachos in a World Cup qualifier at Washington, D.C., in 2001. The U.S. won this tournament in 1991, 2002, 2005 and 2007, and the Americans haven’t failed to reach the semifinals since 2000, when they were defeated by Colombia on penalty kicks in the quarterfinals

Forward Brian Ching was the only regular on the field, with the others dispersed to their clubs or on vacation ahead of the European season.

Jimmy Conrad, U.S. captain for the game, left the field in the 44th minute after he was hit in the face, which drew blood. Conrad has a concussion and his status for Thursday’s game was not immediately known.

The United States was already short-handed because four of the 23 players on the original roster returned to their European clubs: forwards Charlie Davies (Sochaux) and Freddy Adu (Benfica), and defenders Steve Cherundolo (Hannover) and Michael Parkhurst (Nordsjaellands). Midfielder Benny Feilhaber also went back to Aarhus after playing for the U.S. in the first round.

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Panama, which lost to the U.S. on penalty kicks in the 2005 Gold Cup final, went ahead when Perez scored about 45 seconds into stoppage time. He beat goalkeeper Troy Perkins with an acrobatic right-footed kick for his third goal of the tournament.

Beckerman tied the score after Davy Arnaud cut back a cross for him.

“I let the swing and fortunately it went in,” Beckerman said.

Notes: The Americans practiced this week across the street at the Philadelphia Eagles facility, where they chatted with Brian Westbrook and David Akers. ... A crowd announced 31,087 attended the doubleheader, with about 75 percent of the lower bowl full at Lincoln Financial Field and maybe 2,000 fans were scattered around the second level. The U.S. is bidding to host the World Cup in 2018 or 2022, with FIFA due to make a decision in December 2010, and Philadelphia hopes to be selected as a site. ... This was the U.S. men’s national team’s first match in Philadelphia since a 4-0 loss to Israel on Sept. 25, 1968.

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