EVEN Sloane Stephens didn't really think she could beat Serena Williams, not before she went to bed on Tuesday night anyway.
But when she woke up yesterday morning she thought what the hell, just give it your best shot.
That's exactly what she did, conjuring up the biggest upset in recent times by beating Williams 3-6 7-5 6-4 to earn an Australian Open semi-final match-up against world No.1 Victoria Azarenka.
"Uhm, last night I was thinking about it and I was like, someone asked me like, 'Do you think you can win'?" the 19-year-old said.
"I was like, 'Yeah, I think so', but I wasn't like too clear about it.
"Then this morning when I got up, I was like, 'Look, dude, like, you can do this. Like, go out and play and do your best'."
Her best didn't look like it would be good enough when Williams took the first set, but the teenager's prospects changed dramatically when the tournament favourite needed a medical time out to get treatment on a back complaint late in the second set.
After the match Williams refused to use the injury as an excuse, although it clearly hampered her game, particularly her serve.
"It's fine," she said.
"Everyone at this stage in the locker room has something wrong with them, so it's fine - there's no excuse there."
Questioned further, Williams said, "A few days ago it just got really tight and I had no rotation on it. I went for this drop shot in the second set today and it just locked up on me. It was a little painful, and I couldn't really rotate after that. But it's okay. It was what it was."
Stephens is the first American teenager to reach the semi-finals of a Grand Slam since Williams achieved the feat at the 2001 US Open.
Azarenka earned her place in today's semi-final by downing Russian Svetlana Kusnetsova 7-5 6-1.
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