Porto secured a second straight win in the Champions League with a 3-0 defeat of Marseille that all but ended the French side's hopes of qualifying from their group.
Moussa Marega scored early for the Portugal champions, Sergio Oliveira doubled the home side's lead with a first-half penalty, and Luiz Diaz completed the scoring in the 69th minute.
After a seven-year absence, Marseille's return to the elite tournament is proving a nightmarish experience. The 1993 champions have now lost their first three matches in Group C and have yet to score a goal in the competition. With its loss, Marseille became only the second team to lose 12 consecutive matches in the Champions League after Anderlecht.
Manchester City leads Group C with nine points, three more than Porto. Olympiakos, which lost 3-0 to City in the group's other match, is third with three points.
Despite the changes made by coach Andre Villas-Boas following last week's 3-0 loss to City, Marseille created very little in a sterile display and was once again overwhelmed.
The hosts broke the deadlock inside the first five minutes as Jesus Manuel Corona made the most of a ricochet off a Marseille defender to win the ball inside the area and crossed it to Marega at the far post. The Porto forward cooly tapped it into an empty net.
Marseille responded with a raid from Florian Thauvin, who was fouled by Malang Sarr inside the Porto box. But Dimitri Payet fluffed his spot kick horribly over the bar.
Marseille was punished a second time in the 25th minute after Jordan Amavi conceded a penalty with a clumsy tackle. Sergio Oliveira expertly took the kick to send the ball past Marseille goalkeeper Steve Mandanda into the bottom left corner.
Marseille's best occasion came in the 45th minute when Alvaro was found unmarked in the box from a corner, only for the Spanish defender to send his header over the bar.
Diaz added luster to Porto's win with a beautiful goal on the counter after the interval, scoring with a low shot at the far post from Corona's backheel pass.
