For 60 minutes, Panama looked like Central America's newest powerhouse. Thirty minutes later, they were just hoping to avoid a humiliating draw.
The Panamanians led 3-0 and had a man advantage on Tuesday, but short-handed Guadeloupe scored twice to force a frantic finish in a 3-2 loss.
"We shouldn't have had as many problems as we did at the end of the game," said Panama coach Julio Cesar Dely Valdes. "We had the game under control, but we struggled at the end."
Brice Jovial scored both goals for Guadeloupe after coming off as a substitute at halftime.
For the first hour, it appeared that Panama would continue this year's trend of lopsided Gold Cup results.
Luis Henriquez nearly gave the Panamanians a spectacular lead in the 9th minute, but his shot from 55 yards sailed just over the bar.
Blas Perez made it 1-0 in the 22nd minute, knocking a loose ball past goalkeeper Franck Grandel from six yards. Two minutes later, Luis Tejada beat two defenders in the box and side-footed the ball into the corner.
Things got worse for Guadeloupe before halftime, when Michael Tacalfred was shown a straight red card for a foul on Henriquez.
"I was not in a position to see the foul, so I can not give a judgment," said Guadeloupe coach Roger Salnot. "They had more possession after that because of the red card, but the better team won. The result was a fair one."
Panama had a third goal called back in the opening seconds of the second half, but made it 3-0 on Gabriel Gomez's penalty kick in the 57th minute.
The momentum changed quickly after that.
Guadeloupe got on the board in the 63rd when Jovial took advantage of a poor defensive header on the edge of the box. Panama's Jaime Penedo made the initial save, but Jovial scored on the rebound.
Jovial's sliding tap-in of Rochard Socrier's cross made it 3-2 with 18 minutes left, but Panama held on for the victory.
"We lost control of the match a little bit," Perez said. "In the end, the result went to us, but we have to eliminate the mistakes."
Panama's Adolfo Machado was taken from the stadium in an ambulance after suffering an apparent head injury in a collision late in the game. Dely Valdes said he did not have an update on Machado's condition after the game.
"We do not have surfaces like this at home," Salnot said of the grass, which had been criticized earlier in the week. "We were happy to play on it."