Serena Williams survives Christina McHale scare

After a less than impressive display, Williams gathered herself enough to serve the match out to love.

She had earlier shown her displeasure at her own performance, throwing her racket behind her and into the lap of a court official.

She thought she had won the first set and was walking back to her chair after a McHale forehand was called long with the world number one 5-4 and 40-30 up.

To her chagrin, however, a Hawkeye challenge showed the ball brushing the baseline.

McHale went on to win the game and force a tiebreak in which a rattled Williams made a string of errors, including two double faults, before burying a forehand into the net to lose the set. Furious as she sat down, she hammered her racket into the ground in frustration before hurling it behind her.

But the 34-year-old put the disappointment behind her and showed the battling form that has won her six Wimbledon crowns to take the next two sets, closing out the two-and-a-half hour match with three aces.