World champions Italy made a strong start to the men's Olympic tournament Thursday, comfortably overcoming Honduras 3- 0 in their Group D opener while Brazil needed a late goal from Hernanes to overcome Belgium in Group C.

Sebastian Giovinco put the Azzurri in front on 41 minutes in Qinhuangdao while Giuseppe Rossi made it 2-0 on the stroke of half- time from the penalty spot.

Any chance of Honduras getting back into game ended seven minutes afer the restart when Robert Acquafresca made it 3-0 for Italy with his side's second penalty of the game. Carlos Pavon missed a penalty for Honduras.

Brazil, meanwhile, struggled for long periods against a resilient Belgium side but secured all three points when Hernanes fired home from inside the area. Belgium lost SV Hamburg's Vincent Kompany on a red card.

In Group B, Stuart Holden scored the only goal of the game in the United States' 1-0 win over Japan, sending a low shot that squirmed under goalkeeper Shusaku Nishikawa, while Serbia came from a goal down to salvage a 1-1 draw against Australia.

Ruben Zadkovich put the Australians in front on 69 minutes but Slobodan Rajkovic levelled matters with a strong near-post header 12 minutes from time.

In Thursday's later games, defending champions Argentina take on Ivory Coast in Group A, the Netherlands face Nigeria in Group B, hosts China play New Zealand in Group C and South Korea tackle 2000 champions Cameroon in a Group D encounter.