Serena Williams: 'Australian Open spectators helped me beat Garbine Muguruza'

Serena Williams has paid tribute to Australian Open spectators, claiming that those watching on "really helped" her during this morning's match against Garbine Muguruza.

The world number one was struggling at a set down when a fan cried out some advice from the Rod Laver Arena stands.

Williams appeared to heed the words of wisdom as she battled her way to a 2-6 6-3 6-2 victory to book a place in the quarter-finals of the Grand Slam event.

"There's coaches everywhere out here," she quipped. "Someone in the crowd was like, `Come on Serena use spin!' and I was like, `OK'. Thank you guys, you really helped me."

Next up for Williams is a meeting with last year's beaten finalist Dominika Cibulkova in the last eight of the competition.