LONDON (Reuters) - Madison Keys completed a hat-trick of wins over luckless Frenchwoman Alize Cornet as the American ninth seed reached the Wimbledon fourth round for the second successive year with a 6-4 5-7 6-2 victory on Saturday.

Cornet had fought back to level the contest at one-set all but when she rolled her ankle to crash heavily onto the slick surface in the second game of the decider, it completely knocked her off her stride.

Within the blink of an eye Keys had opened up a 4-0 lead and while Cornet, ranked 61st in the world, broke in the fifth game to raise hopes of a fightback, her challenge quickly hit the buffers.

A forehand that went long on match point saw Keys wrap up victory and book a last-16 meeting with world number five Simona Halep of Romania.

(Reporting by Pritha Sarkar, editing by Ken Ferris)