Andy Murray into Shanghai Masters quarter-finals after beating John Isner

Andy Murray has beaten American John Isner 6-7 6-4 6-4 to reach the quarter-finals of the Shanghai Masters.

It was Isner who took the first set, with his trademark big serve helping to overcome a frustrated Murray to win the tie-break 7-4.

Murray came back, however, with the Scot managing to break the serve of the world number 13 with an impressive backhand winner before defending a break threat from the American and holding on to secure the second set.

The world number two wrapped things up in the third, once again breaking Isner before going on to seal victory with some calm, composed play.