Besiktas moved a step closer to the Europa League round of 16 after a 2-0 win at Sporting Braga, while Olympiakos also won on Tuesday.
Turkish giants Besiktas capitalised on playing most of their clash in Braga with a numerical advantage, ending the Liga Sagres club's 12-match unbeaten run.
Goals from Tomas Sivok and Simao wrapped up the win at Estadio Municipal de Braga, with Carlos Carvalhal's men to take the advantage into the second leg of the round-of-32 encounter.
After an even opening, the game turned just before the half-hour mark when Braga attacker Helder Barbosa was sent off after picking up two yellow cards - the second for diving.
The visitors only needed eight minutes to take advantage when Sivok rose unmarked to head in the opener from a Manuel Fernandes corner.
Besiktas took further control of the tie on 58 minutes, when two of their three Portuguese stars combined for the second.
Fernandes played Simao through, and the former Sporting Lisbon and Benfica midfielder poked his effort past the advancing Quim.
Braga, last year's runners-up, failed to pull a goal back in the closing stages and face a huge task heading to Istanbul.
Meanwhile, Olympiakos recorded a 1-0 first-leg win over Rubin Kazan in Russia thanks to some heroics from debutant Roy Carroll.
The Greek champions took a 71st-minute lead through David Fuster's deflected effort, before Carroll was called upon to help his side hold onto their advantage.
First-choice goalkeeper Balazs Megyeri was sent off after bringing down Gokdeniz Karadeniz moments after the opener, and Carroll was brought off the bench.
The former Manchester United shot-stopper, a January signing, produced a superb save to deny Bibras Natcho from the spot as Olympiakos held on for a crucial away win.