Italian Jasmine Paolini is into the Wimbledon quarter-finals after a tearful Madison Keys retired with an injury in the deciding set.

The American, 29, was forced to stop with the score locked at 6-3 6-7 (6-8) 5-5 on Court One.

Keys appeared to pick up the injury when she hit a forehand while serving for victory at 5-2 in the final set.

She took a medical timeout at the change of ends when leading 5-4 and was treated before leaving the court.

The 12th seed reappeared with strapping high on her thigh and was clearly hampered by the injury.

Paolini, 28, broke the serve of Keys again to level at 5-5 before Keys decided she could no longer continue.