Besiktas stayed perfect in Champions League Group G with a 2-0 win over RB Leipzig after first-half goals from Ryan Babel and Talisca on Tuesday.
The Turkish side has six points from two games in Group G, three more than Porto, with last year's semifinalist Monaco and Leipzig on one point. Porto won 3-0 at Monaco in the group's other match on Tuesday.
Besiktas, now unbeaten in 10 European home matches, had never beaten German opponents in seven previous attempts in European games.
Leipzig, who played their maiden European away match, enjoyed most of the ball possession and had 19 attempts at goal but were made to pay for their inexperience.
Babel netted the opener in the 11th minute, putting in a first-timed shot after good work on the wing from Cenk Tosun.
It was 2-0 just before half-time as Anderson Talisca beat his marker to head in Ricardo Quaresma's cross.