Didier Drogba scored on his debut as Chelsea brushed aside AS Roma 3-0 in the Champions World Series in Pittsburgh on Thursday.

Both teams finished with 10 men after Chelsea's Mateja Kezman and Olivier Dacourt of Roma were sent off in the 66th minute at Heinz Field.

England midfielder Joe Cole put the big-spending Londoners in front in the 11th minute before Serbia and Montenegro marksman Kezman doubled Chelsea's advantage after 63 minutes with his fourth goal in three pre-season friendlies.

Ivory Coast striker Drogba, who last week became the club's record buy when he joined from Olympique Marseille, made sure of victory with a 68th-minute goal.

Chelsea began their North American tour with a 4-2 win over Celtic in Seattle last Saturday.

The Champions World Series features 11 friendly matches at eight venues across the United States and Canada, involving club sides from England, Italy, Scotland, Portugal, Germany and Turkey.

The next match is on Friday with Porto facing Liverpool in Toronto.