LONDON, United Kingdom (AFP) – Defending champion Serena Williams narrowly survived a major scare at Wimbledon on Friday, coming from behind to overcome gritty US compatriot Christina McHale in a thrilling second round encounter on Friday.

The world number one defeated McHale 6-7 (7/9), 6-2, 6-4 in two hours and 29 minutes on Centre Court, only just avoiding what would have been her earliest-ever Wimbledon defeat.

The six-time Wimbledon champion will face Germany’s Annika Beck for a place in the last 16.

“It was a really good match. She played great and she always plays great against me,” Williams said.

“I know mentally no-one can break me. I knew, down a break in the third, that I was going to have to put my mind in it and that’s what I did.”

Several times throughout the match, Williams was left cursing the bounce of the ball or screaming at the heavens as she struggled to find her form against the world number 65.

McHale was set point down in the 10th game of the first set but challenged when Williams thought she had won the point — and Hawk-Eye technology showed the tiniest sliver of the ball was in, giving the outsider a reprieve.

McHale recovered and fashioned a few set points for herself before sealing it on the tie break.