John Isner came back from losing a set to reach the second round of the Shanghai Masters with a 7-6[5] 1-6 6-3 victory over Pablo Andujar.

Isner was forced to battle for his opening game of the contest as Andujar created three break points, but the American was able to hold his serve.

From then on, it was a tight match as games went by the way of serve and a tie-break was required to decide the opening set.

Only one break of serve occurred in the showdown and it was Isner who came out on top to take a one-set lead on the hard court.

Andujar bounced back in the second set by earning a swift double break, leaving Isner with just one game on the board as the scoreline drew level in Shanghai.

However, Isner struck in the third set as he broke his opponent's serve once and went on to wrap up the contest to continue his campaign in China.