Mario Gomez & Arjen Robben Got 1 goal each to give high advantage in 2nd leg Of QF.
Gomez put Bayern ahead with his 11th goal of the competition just before halftime, with Marseille goalkeeper Elinton Andrade to blame for letting the ball slip under his body, and Robben scored a clinical second in the 69th after a quick one-two with Thomas Mueller.
Out of form, hampered by injuries and suspensions, and jeered by it own fans, Marseille barely tested Bayern keeper Manuel Neuer at Stade Velodrome as it slipped to its eighth defeat in the last nine games.
Andrade, Marseille's third-choice goalkeeper, was playing instead of the suspended Steve Mandanda and looked nervous in the first half, spilling an easy catch and hacking a routine clearance away for a corner instead of down the field.
When Gomez struck from the edge of the area, the ball came straight at Andrade, yet he let it roll under his arm and into the bottom right corner. Andrade was playing only his ninth game in three years, and it will be one to forget.But not for Gomez, who has been in prolific form with 23 goals in the league, and moved one behind Barcelona star Lionel Messi in the Champions League scoring charts.
Marseille's fans were in unforgiving mood and refused to encourage the players at the start of the game, even holding up one banner, which said: "Ce soir on est comme vous: on ne sert a rien" (Tonight we're just like you: good for nothing). Other banners, bearing the names of supporters groups, were held upside down in protest.
They did not spare Bayern winger Franck Ribery, either.
He had hoped for a warm welcome from the fans who worshipped him when he played for Marseille from 2005-07, but his name was jeered as soon as the stadium announcer read it out, and then every time he touched the ball.
Marseille had its only clear-cut chance early on when Neuer palmed away Andre Ayew's header and striker Loic Remy, shaking off a thigh injury to start up front, smashed the rebound into the side netting.
After 20 minutes, the fans' strike was over and they started chanting for Marseille, which tried to drag the German side into a physical battle. Marseille closed down space well and stopped Bayern from developing any sort of fluency, and was also winning some crunching tackles in midfield.
Ayew broke free down the left and shot into the side netting in the 28th, although it would have been difficult for the Ghanaian winger to beat Neuer from such a tight angle. Remy's drifting runs and movement off the ball kept Bayern's center halves busy, but the supply to the France forward was often predictable and Bayern dealt easily with long balls over the top.
After a brief spell on top, Marseille fizzled out and Bayern took the lead in the 44th minute after a Marseille move broke down.
Winger Mathieu Valbuena lost the ball to right back Philip Lahm, who passed it to Ribery, who in turn fed Robben down the right. The Dutchman played in Gomez, who took his chance with a drive that squirmed under Andrade - while his teammates continued to complain that the ball had hit Lahm's hand in the build-up to the goal.
Andrade's confidence was clearly shaken after his blunder and, when Robben lobbed a pass over the defense for Mueller to chase in the 52nd, he was slow to come off his line. But Mueller could not keep the ball down. Andrade did atone somewhat for his error when he kicked away Mueller's shot in the 58th.
Marseille coach Didier Deschamps brought on Brazilian striker Brandao with 20 minutes to go and pushed Remy out wide right, but it made little difference.
Robben made the game safe after swapping passes with Mueller on the edge of the penalty area and curling the ball past Andrade. Ribery turned to applaud the Bayern fans after he came off late in the game to a chorus of whistles from the Marseille fans.
Robben was in fine form, darting down the right late on and blazing the ball over when Gomez was in a better position. But with one foot in the semifinals, and having pulled to within one goal of Messi, it was hardly the moment for Gomez to complain.
