Panama squandered a 1-0 lead less four minutes into the second half and spent the rest of regulation and overtime trying to blunt U.S. attacks while struggling to generate a few of its own.
The visitor briefly held the lead after Blas Perez blasted a deflected corner kick past Troy Perkins in first-half stoppage time, but once Kyle Beckerman had nailed a first-time strike from distance into the top corner early in the second half, the Americans controlled the action by moving the ball crisply and plowed steadily on despite a succession of rough fouls.
Panama committed 20 fouls and the Americans 19 in a choppy match that boiled over at the final whistle when the Panamanians surrounded Mexican referee Benito Archundia, presumably for disciplining Ramon Torres for his savage karate kick into the gut of Kenny Cooper as he collected a cross near the end of the first overtime.
Even in the strange netherworld known as Concacaf, that's a penalty, and Cooper shook off the blow to drill his kick off the inside of the goalpost.
Panama had already fatigued noticeably in the second half and seldom mustered a notable threat. The USA dominated in shots, 16-3, but seldom tested. Panamanian keeper Jose Penedo, who needed to make just three saves, one of them a desperate dive to turn away a blast from left back Heath Pearce.
Perkins didn't register one save while collecting crosses and through balls cleanly as the Americans resolutely pressed Panama in most parts of the field
The incisive approach work of Beckerman and Stuart Holden often pushed the ball through the middle third into Panama's defensive zone, and Panama, unable to keep pace, followed defender Felipe Baloy's example of knocking down forwards Davy Arnaud and Brian Ching at every opportunity.
Ching headed a Holden free kick off the post in the eight minute with Penedo utterly beaten, and a few more squandered chances added up to a 1-0 deficit at halftime. Defender Clarence Goodson had just replaced Jimmy Conrad, who'd been knocked senseless in a collision, and Baloy evaded Goodson's marking to head a corner kick that caromed off Holden for Perez to smash into the net with a point-blank volley.
Stunned and stung, the Americans came out flying for the second half, with Beckerman working all over midfield as Holden and Arnaud swapped passes with Ching and Rogers. Beckerman scored after Rogers' deep cross in the 49th minute had cleared the back line. Arnaud, backing up, chose to play it with his feet and his diagonal ball ran behind Holden near the penalty arc into the path of Beckerman, who cracked it into the top corner.
More combinations and sequences produced numerous shots to no avail but the pumped-up Americans didn't let up. Beckerman and Holden were too smart and too quick, for Panama to contain, and though Rogers lost a lot of his dribbles, he also chased back to recoup his losses.
Hasty high balls were won by Chad Marshall and Goodson; Pearce and Jay Heaps secured the corners. Fatigue and Panamanian fouling failed to deter them.
If their finishing lacked bite, their drive and conditioning smothered their opponents attempts to get back in the game.
Cooper replaced Arnaud in the 77th minute and fluffed a header shortly thereafter when Pearce sprinted and slid to the touchline to keep a ball in play to swerve a great cross. Other chances were squandered, though Pearce drilled a shot in overtime that Penedo dove right to turn away, before Holden's cross to Cooper in the 104th minute forced Torres' reckless foul.
The FC Dallas forward had shot poorly up to that point and needed a minute or two of recovery time, yet he manned up admirably. A long run-up yielded a low right-footer; Penedo picked that side, but had to pick the ball out of the net after it caromed off the post and over the line.
No doubt the U.S. deployed the right personnel and utilized the proper strategies to win this game, yet it also stubbornly ignored harsh play, fatigue and frustration to get the job done.
July 18 in Philadelphia
USA 2 Panama 1. Goals: Beckerman 49, Cooper pen. 105; Perez 46+.
USA -- Perkins, Heaps, Marshall, Conrad (Goodson, 46+), Pearce, Holden, Pause, Beckerman, Rogers (Evans, 110), Ching, Arnaud (Cooper, 77)
Panama -- Penedo. R.Torres, Baloy, Gun, Moreno, Gomez, M.Torres, Escobar (Phillips, 78), Barahona (Herrera, 96), Garces, Perez
Yellow Cards: USA -- Conrad 11; Panama -- Perez 25, Baloy 63, R.Torres 104, Perez 120.
Red Cards: Panama -- Baloy 120, Perez 120.
Referee: Benito Archundia (Mexico).