Big-serving American John Isner came through in straight sets over Olivier Rochus in a little-vs-large first-round Olympic match at Wimbledon this afternoon.

Diminutive Rochus held strong on his own serve in the opener on No. 2 Court as neither men found a break and the set went to a tie-break.

Isner was dominant in racing to a 5-0 lead before closing out the breaker 7-1 to take the first set in 50 minutes.

Belgium's Rochus lost his serve in the opening game of the second and couldn't find a way back as Isner held to-love game after game to take the set and match 6-4.

The 27-year-old, seeded tenth at the Games, will next face Tunisian Malek Jaziri in the second round.