Serena out, Coco in as tennis sees past, future at Australian Open

American veteran Serena Williams sensationally crashed out but 15-year-old Coco Gauff went through as tennis got a glimpse of its past and future at the Australian Open on Friday.

Williams' bid for a record-equalling 24th Grand Slam was halted by the unlikely figure of China's Wang Qiang, who triumphed in three tough sets -- after winning just one game when they played at the US Open in September.

Gauff then stepped up her giant-killing Melbourne debut as she ousted Japanese defending champion Naomi Osaka, 22, in dismissive style, winning 6-3, 6-4 in just 67 minutes to reach round four.

"Oh my gosh. Two years ago I lost first round in the juniors and now I'm here -- this is crazy," said the teenager, who upset Venus Williams in the first round.

With Williams now 38, 23 years older than Gauff, the two players are at opposite ends of their careers.

And with Williams' close friend Caroline Wozniacki retiring on Friday, after defeat to Ons Jabeur, it looked like a changing of the guard.

But Williams, who has now had eight winless Grand Slams since returning from childbirth, said she hadn't given up hope of matching Margaret Court's 47-year-old record for Grand Slam titles.

"I definitely do believe (I can equal it) or I wouldn't be on tour," said Williams, a seven-time winner at Melbourne Park.

Williams was the bookies' favourite to lift the trophy for the eighth time but she came unstuck against a determined Wang, who won 6-4, 6/7 (2/7), 7-5.

- 'People thought I was crazy' -
================================
"People thought that I was crazy being from a small country. But I made it happen."