Last season's finalists AC Milan [ Images ] and Liverpool were stunned in their group games in the UEFA [ Images ] Champions League [ Images ] on Wednesday.

A last-minute goal from Scott McDonald gave Celtic a 2-1 victory over holders AC Milan in their Group D clash while Olympique Marseille [ Images ] stunned Liverpool with Mathieu Valbuena's classy goal earning a 1-0 win at Anfield in Group A.

Valbuena took a return pass from Bolo Zenden before curling in a 25-metre shot off the underside of the bar in the 76th minute after Momo Sissoko was tackled just outside his area.

But it was not a fluke victory for new coach Eric Gerets in his first game in charge of a Marseille side that has won just one of their nine domestic league games this season.

Liverpool did not really threaten until the final minutes when Fernando Torres [ Images ] hit the post with a close-range shot.

AC Milan match ended on a sour note as goalkeeper Dida was carried off on a stretcher after being struck in the face by a supporter who raced on to the pitch to celebrate.

Celtic went ahead after a dull, rain-lashed first half when captain Stephen McManus bundled in a close-range shot at the back post after Aiden McGeady's corner skidded across the face of goal in the 62nd minute. The ball took a last touch off Milan's Yoann Gourcuff.

The Italians levelled from a penalty six minutes later with Kaka [ Images ] sending Celtic keeper Artur Boruc the wrong way, before McDonald grabbed the late winner.