Adu came on with Benfica trailing, 1-0, and it won on three late goals. Adu's goal was his second league goal and fifth overall since arriving in Lisbon from Real Salt Lake in the summer.
Benfica in second place, four points behind Porto, which beat Vitoria Setubal, 2-0.
ENGLAND. Bobby Convey continued his comeback with his second straight start for Reading and has an assist on the Royals' goal in a 2-1 loss at Manchester City. Benny Feilhaber played for Derby County the first time in seven weeks when he came on for the last six minutes of the Rams' 2-0 loss to Chelsea.
GERMANY. Heath Pearce made his third straight appearance off the bench for Hansa Rostock in its 2-0 loss at Hamburg.
MEXICO. Americans had mixed fortunes in the Mexican playoffs. Edgar Castillo started for regular-season leader Santos, which rolled into the semifinals with a 3-2 win over Morelia and 5-2 victory on aggregate. Michael Orozco started for San Luis in its 1-0 loss to Guadalajara that knocked it out, 2-1, on aggregate.
NETHERLANDS. Michael Bradley, back from international duty in South Africa, played the entire 90 minutes in fourth-place Heerenveen's 3-2 loss to Graafschap that snapped its five-game winning streak.