Benfica skipper Luisao headed a second-half winner to send his side top of their group after a 2-1 defeat of Champions League rivals Galatasaray at the Estadio da Luz.
Galatasaray were looking to leapfrog Benfica at the top of Group C with victory, but after Lukas Podolski had cancelled out Jonas' opener for Benfica, long-serving captain Luisao ensured it is the Portuguese who sit in pole position.
The home side survived an anxious final five minutes with 10 men after Gaitan was shown his second yellow card for his foul on Emre Colak.
Benfica made the brighter start and threatened twice through Gaitan and Jonas in the opening 20 minutes before Podolski's goalbound shot was blocked by Luisao.
Dutch midfielder Wesley Sneijder had Galatasaray's first shot on target midway through the first half, but neither side created a clear-cut chance before the interval.
Benfica broke the deadlock through Brazilian Jonas in the 52nd minute, drilling home his shot past visiting goalkeeper Fernando Muslera following a penalty area scramble.
The home side's lead was short-lived though. A ball into the area took a lucky deflection off Galatasaray midfielder Bilal Kisa and fell to Podolski, who fired the chance past Benfica goalkeeper Julio Cesar six minutes later.
Benfica's Mexico international Raul Jimenez flashed a long-range shot wide of Muslera's post before Luisao headed the Portuguese back into the lead in the 67th minute.
Jimenez collected a short corner and chipped the ball into the penalty area for Luisao to head powerfully home into the top corner.
Muslera twice denied Benfica a third in quick succession when keeping out Gaitan's free-kick and Jimenez's effort off the rebound in the 72nd minute.
Gaitan's second yellow card in the 85th minute ensured a nervous finish for the home side. Selcuk Inan's angled shot was inches off target and in stoppage time Umut Bulut missed an open goal on the follow up after Cesar had saved his initial shot.