Olympiakos Piraeus scored three times in the last 17 minutes to stun Werder Bremen 3-1 in their Champions League Group C match on Wednesday.

Bremen took a 32nd minute lead when Hugo Almeida blasted in a Daniel Jensen cross but Ieroklis Stoltidis tapped in the Olympiakos equaliser in the 73rd minute after a blunder by Bremen's reserve goalkeeper Christian Vander.

The game swung the Greeks' way nine minutes later when Christos Patsatzoglou slammed home a long-range shot and Darko Kovacevic made sure of the points in the 87th minute, tapping in another rebound after Vander again failed to hold on to the ball.

The goals handed Bremen their second defeat in two matches, while Olympiakos went top of the group with four points, just ahead of Real Madrid, who also have four points.

Porto snatch late victory

Ricardo Quaresma scored a stoppage-time goal to give Porto a 1-0 victory over Besiktas in their Champions League Group A match on Wednesday.

Porto had to work hard to stave off growing pressure from the home side in the later stages of both halves, with Besiktas creating a series of chances.

But it was Porto who broke the deadlock when midfielder Quaresma poked the ball past Besiktas keeper Hakan Arikan from close range in the second minute of stoppage time.

The result lifted Porto to second in the group with four points, two behind leaders Olympique Marseille and three ahead of Liverpool. Besiktas are without a point after a second loss.

Schalke too good for Rosenborg

Second-half goals steered Schalke 04 to a 2-0 victory over Rosenborg Trondheim in their Champions League match in Group B on Wednesday.

Midfielder Jermaine Jones broke the deadlock at the Lerkendal Stadium in the 62nd minute with a left-foot shot off a pass from Ivan Rakitic.

Striker Kevin Kuranyi sealed the victory in the 89th minute, breaking free, evading defender Christer Basma and putting the ball past Rosenborg goalkeeper Lars Hirschfeld.

Rosenborg, who had held Chelsea to a surprise 1-1 draw at Stamford Bridge two weeks ago, paid the price for failing to take their chances in the second half.

Schalke, who got their first points on the board, are third in the group -- level on three points with Valencia and one behind leaders Chelsea after the Londoners' 2-1 win in Spain.