Club Atlético de Madrid took leadership of Group G after coming from a goal down to beat their UEFA Champions League bogey team FC Porto at the Estádio do Dragão.
Arriving on the back of a superb weekend win in the Madrid derby, Diego Simeone's side fell behind to Jackson Martínez's first-half header, but recovered as captain Gabi set up goals for Diego Godín and Arda Turan after the break. Porto had been unbeaten in four previous meetings with Atlético in the competition, but must now look to recover on matchday three against FC Zenit while Atlético go to FK Austria Wien.
Backed by a vibrant home crowd, Porto took the game to their visitors from the start, playing at a high tempo and pinning them back. Silvestre Varela had the first meaningful effort on goal, but was unable to get a clean connection on his header from Josué's cross and the ball looped into Thibaut Courtois' arms.
The pressure did tell in the 16th minute, when Jackson escaped the attentions of Godín to dive full length and head in Josué's free-kick. Lucho González volleyed over the top from the edge of the area, then Jackson had another attempt blocked by Miranda as the Dragons pressed for a second.
Atlético almost snatched an equaliser with their first strike of note, a speculative long-range effort by Raúl García landing on the roof of Helton's net with the goalkeeper back-pedalling furiously. Arda then hit a shot over from the edge of the box after a neat move down the right, before García's header from a Gabi corner rattled the crossbar as Simeone's men began to motor.
The Spanish outfit continued to show more purpose as the second half got under way. The advancing Filipe Luis had a shot from distance deflected narrowly wide by Nicolás Otamendi, but the equaliser was not long in arriving. Just before the hour Godín enjoyed a happier conclusion to a set piece than at the same end in the first half, beating Helton to nod in from Gabi's delivery.
All of a sudden it was Atlético who appeared sharper to the ball, allowing Paulo Fonseca's charges no time to settle in possession, even in their own half. García seemed to have spurned the chance to win the game when he was sent through by Arda for a shot that was charged down by Helton, yet there was still time to make amends. Gabi's clever free-kick caught out the Porto back line and released the Turkey midfielder to thump the decider high into the net.