By Brian Homewood

MILAN (Reuters) - A hotly-protested goal by Kevin-Prince Boateng set AC Milan on their way to a shock 2-0 win over Champions League favorites Barcelona in their last-16 first-leg tie on Wednesday.

Barcelona, who eliminated Milan last season, surrounded the referee claiming Cristian Zapata had handled the ball before it landed at the feet of Boateng who smacked it into the net in the 57th minute.

Barca, who had dominated possession in their familiar style, lost their grip on the game after the incident and were sunk by a second goal from Boateng's fellow Ghanaian Sulley Muntari.

The return leg is at the Nou Camp on March 12.

(Editing by Alison Wildey)