But the gritty victory virtually assured the Americans passage into the semifinals of Concacaf Olympic Men's Qualifying while eliminating Panama. Only if shorthanded Cuba -- which lost to Honduras, 2-0, in the first match of a doubleheader after seven players defected Tuesday and Wednesday -- can beat Panama in its final game and somehow surpass the USA -- should it lose to Honduras in its finale -- on goal difference can the Americans fail to advance.
Of course, the final day of Group A play on Saturday might set up Group B shenanigans the following day, thanks to the staggered schedule of matches as decreed by Concacaf.
Rather than play both final sets of group games on the same day, if not simultaneously, Concacaf arranges the schedule so the Group B teams will know before they kick off the final placings in Group A.
Since the runner-up in one group plays the top team in the other, that knowledge can affect whether a team prefers to win its group or finish second. That may give Mexico, rather than the home team, an edge. Only in Concacaf.
Still, for the Americans, they will take the field against Honduras knowing their place in the semifinals is most likely secure, and they can win the group simply by winning the game. And Mexico may not have any wiggle room after tying Canada, 1-1, in its opener Wednesday.
Freddy Adu scored from the penalty spot after Jozy Altidore had been uprooted by Panamanian goalkeeper Jose Calderon while chasing down a superb ball from Eddie Gaven, one of two players - Adu being the other - playing in support of Altidore in a revamped 4-3-2-1 formation.
Head coach Peter Nowak changed personnel as well as shape. Central defender Nathan Sturgis moved to left back, midfielder Maurice Edu dropped to central defense and lined up alongside Michael Orozco, one of three starters who didn't see any action against Cuba. The other two were right back Marvell Wynne and midfielder Stuart Holden, who played in a midfield trio along with Dax McCarty and Sacha Kljestan.
Instead of the numerous periods of fluid, cohesive play the U.S. generated against Cuba, the Americans scrapped and scratched to subdue the pesky Panamanian attackers and on the ball had to fight their way through gang tackles and rugged fouls. Holden's brave, skillful runs and occasionally slick touches from Adu and Kljestan seldom led to prime scoring chances. Holden, the third-year Houston Dynamo player, consistently unbalanced the packed Panamanian phalanx and a few times got back into his own penalty area to win duels.
Aside from winning the penalty, Altidore's best moments yielded free kicks that resulted from clattering Panamanian fouls.
"You just have to get in there with them," said Altidore. "They're pushing and kicking, and you just have to do the same thing. You can't let up, and you need to be there for your teammates when they need you. In games like this you can't back down, you just have to go with it."
Edu and Sturgis confidently picked off passes and won tackles, but too often gave balls away in bad spots. Yet so quickly did they and their teammates recover keeper Chris Seitz faced very few shots. Panama coach Alexandre Guimaraes - who as coach of Costa Rica has faced the USA several times -- deployed his players to fill lanes sought by McCarty, Kljestan, Edu and Sturgis as outlets, and got bodies into Adu, Gaven and Altidore as often and as early as possible.
Gaven ran into far more tangles than he avoided yet he set up Altidore with an excellent serve and also cut back a ball from the right flank that caused momentary panic in the Panamanian goalmouth.
"Jozy made a great run, and I just hit it over the top, he did all the rest," said Gaven of the decisive play in the 4141st minute that yielded a caution for Calderon as well as the penalty kick. "It was good work by him."
The tactics and fouling jarred the Americans out of any rhythm for most of the match, yet they constantly held firm under pressure and patiently picked their moments to lunge into tackles or step into challenges. McCarty buzzed and worked as he had against Cuba, but his passing and timing weren't quite as crisp, and he took so many tactical fouls in the first half a more apt name might have been McCardy, but he avoided getting cautioned.
Still, Jamaican referee Dave Peterkin handed out seven yellows, with Wynne, Adu and Sturgis the Americans to be booked. Aside from a pair of Gabriel Torres headers off set plays, Panama broke free for a clean chance at goal. Once it had the lead, the U.S. defended doggedly, with McCarty digging out balls, Edu cutting off passes, and Kljestan winning two important aerial duels to head clear.
Nelson Barahona ran onto a nice diagonal ball with about 15 minutes to play and wastefully dragged his shot well wide of the far post. A clumsy foul by Sturgis in stoppage time earned him a caution and gave Panama a free kick in the attacking third yet once again the Americans repelled the danger.
"We knew they were going to play hard, and we needed to match their level of intensity on every play, whether it was a header, a loose ball or getting in front of goal," said Kljestan. "We know against Honduras it will be similar, so we're looking forward to that."
March 13 in Tampa
USA 1 Panama 0. Goals: Adu pen. 42.
USA -- Seitz, Wynne, Orozco, Sturgis, Edu, Holden, McCarty, Kljestan, Gaven (Zizzo, 64), Adu (Findley, 90), Altidore (Davies, 90).
Panama -- Calderon, R.Torres, Anderson, Algandona, Machado, Bonilla, Vega (Quintero, 52), Arosemena, Gabriel Torres (Aguilar, 71), Barahona (Rodriguez, 84), Jimenez.
Yellow cards: USA -- Wynne 18, Sturgis 90, Adu 90; Panama -- Bonilla 19, Calderon 41, Quintero 58, Machado 72.
Referee: Dave Peterkin (Jamaica).