Monfils was struggling with a back injury at the start of the fourth set as Ben Shelton advanced to the quarter-finals

Veteran Gael Monfils has rolled back the years in recent weeks with a string of incredible performances, but the Frenchman said he had exceeded his limit after retiring hurt from his fourth-round Australian Open match against Ben Shelton on Monday.

American tennis star Ben Shelton has shown his class after opponent Gael Monfils was forced to retire in the fourth set of their gripping clash at the Australian Open on Monday night. Monfils pulled the pin with 21st seed Shelton leading 7-6 (7-3), 6-7 (3-7), 7-6 (7-2), 1-0 much to the dismay of the crowd.

Gael Monfils rallied from a set down to claim a thrilling 3-6, 7-5, 7-6 (1), 6-4 win over American Taylor Fritz in a third-round match at the Australian Open.

Ben Shelton ground down French veteran Gael Monfils Monday to set up an Australian Open quarter-final against Lorenzo Sonego, who ended teenage qualifier Learner Tien's fairytale run. But again nothing separated them until Shelton ended the resistance of Monfils with a series of winners to take the tiebreak and the veteran retired soon after.