Coach Julio Dely Valdes was upset when Panama's sudden lapse in concentration led to an early goal for Cuba.
Panama didn't need long, though, to regain its aggressive identity and make Valdes smile.
''It came in a moment when Panama was dominating the game, and we were looking to attack,'' Valdes said. ''It's very difficult when you get scored upon because it gets very complicated. We had to continue to pursue the attack.''
Gabriel Torres scored two goals in the first half to help Panama beat 10-man Cuba 6-1 in the quarterfinals of the Gold Cup on Saturday.
Panama, which has three wins and no losses in four Gold Cup games this year, advanced to the semifinals next week in Dallas.
Torres, whose penalty kick in the 25th minute made it 1-1, gave Panama a 2-1 lead 13 minutes later.
Blas Perez assisted on the goal by heading Gabriel Gomez's crossing pass to Torres, who kept the ball from touching the ground and used his right foot to beat goalkeeper Odelin Molina on the right side from 8 yards.
Torres has five goals in four Gold Cup games. He scored twice in Panama's 2-1 group stage win over Mexico.
Cuba played a man down and gave up four goals in the last 32 minutes after Ariel Martinez was given a red card for a hard foul against Perez.
''I don't think it merited a red card,'' Cuba coach Walter Benitez said. ''It was unexpected.''
With Martinez gone from the game, Cuba gave up a flurry of goals.
Carlos Rodriguez put Panama ahead 3-1 in the 68th minute from 12 yards.
Perez added a breakaway goal in the 77th minute to make it 4-1, Jairo Jimenez scored in the 85th minute and Perez again in the 86th.
Losing Martinez was a big blow to Cuba considering that he scored three goals in a 4-0 win over Belize earlier this week.
The Cubans, who have lost 13 of their past 15 Gold Cup games, led 1-0 in the 21st minute when Jose Ciprian's right-footed kick from the center of the box beat goalie Jamie Pendo to the right side.
Panama has allowed one goal or none in eight straight Gold Cup games. The Panamanians lost to the U.S. in the semifinals two years ago.
Valdes liked how Perez, who missed the win over Mexico to fulfill his Major League Soccer obligation to FC Dallas, was active throughout the afternoon with two goals and an assist. It marked Perez's first goals in three tournament games.
''As a forward, he always wants to be accompanied with goals,'' Valdes said. ''We saw today the Blas of always, working very well on the field.''
Though Panama's past four goals came against an outmanned opponent, Valdes was pleased that his team kept attacking to put Cuba away.
''It's not easy to score six goals, including that we could've scored another one, but there are things early that we must improve,'' Valdes said. ''Early in the game, there was too much overconfidence, and we have to be serious when the other team is trying to demonstrate that they are superior.''
Notes: Panama improved to 10-4-4 in all competitions. ... This tournament marks Panama's second straight Goal Cup with no losses in the group stage and quarterfinals. ... Cuba was playing a Gold Cup knockout game for the second time and first since 2003.