Locked in a tight battle with Sloane Stephens, Serena Williams takes out her frustration on her racquet.

Title favourite Serena Williams made a shock exit at the Australian Open as injury derailed her hopes against Sloane Stephens in the quarter-finals.
The 15-time Grand Slam champion led her fellow American by a set and a break, but after being treated for a back spasm in the second set went down 3-6 7-5 6-4.
Williams was heard on court to say it had been the 'worst two weeks' as she has struggled with ankle and back issues, and afterwards she stuck by that assessment.
'For a Grand Slam, absolutely. Absolutely,' she said.

'I'm almost relieved that it's over because there's only so much I felt I could do. I was unaware the microphones picked that up.
'But, it's been a little difficult. I've been thrown a lot of balls these two weeks.'
Asked about the back problem, Williams played it down, saying: 'I think everyone at this stage in the locker room has something wrong with them, so it's fine. There's no excuse there.'
Stephens, 19, is on the verge of breaking into the world's top 20 and was playing in her first Grand Slam quarter-final.
She gave a good account of herself in the opening stages, but Williams looked to have seen off the impressive teenager when she reeled off five straight games from 3-3.
However.