John Isner has edged out Viktor Troicki to earn a place in the third round of the Monte Carlo Masters.

The big-serving American was tested during the second set but he held his nerve to run out a 7-6(4) 7-6(5) winner.

Isner looked strong behind his first serve during the opening set, and although he couldn't find the break, he controlled the tie-break to move into the lead.

The second set saw Troicki create seven break-point opportunities, but Isner produced big serves when required, and after opening up a clear advantage in a tie-break for a second time, he was able to seal victory in one hour 40 minutes.

Isner will now face Rafael Nadal for a place in the quarter-finals.