John Isner is through to the third round of the BNP Paribas Open after a dominant display against Jurgen Melzer.

The big-serving American mustered just two aces in the opening set and got in less than 40 % of his first serves.

However, Isner's returning of Melzer's serve proved crucial as he broke the Austrian to take the opener 6-3.

The world number 20 then found his form on his own serve, dishing up 11 aces and a significantly improved first-serve percentage as he went on to wrap up the second set 6-4 and progress in just over an hour.

Isner now faces South African Kevin Anderson, who beat Federico Delbonis in straight sets.