Melbourne, Jan 24: Fired-up top seed Novak Djokovic powered into the Australian Open fourth round on Saturday, joining sizzling fellow world number one Serena Williams and injury-free two-time winner Victoria Azarenka.
The Serb, whose chances of a fifth Australian crown have vastly improved after Roger Federer's shock exit on Friday, ground down tenacious Spaniard Fernando Verdasco 7-6 (10/8), 6-3, 6-4. He said he was highly motivated and over the virus that hampered his lead up to the season's opening Grand Slam.
"Physically, I feel fit now and I'm always motivated to play well in Australia," said Djokovic.
Williams, vying for a sixth Australian title and the first since 2010, was slow to get in the groove against 26th-ranked Ukrainian Elina Svitolina, going down 6-4 in the first set.
But she shook off the cobwebs under the blazing sun on Rod Laver Arena to rattle through the next two sets 6-2, 6-0. It keeps alive her quest to add a 19th Grand Slam title, which would take her to clear second on the all-time Open Era Grand Slam winners list.
She currently has 18 alongside Chris Evert and Martina Navratilova and is four behind German great Steffi Graf's 22.
"When in doubt just start running as fast as you can, that's what Venus always told me, that helped," said Williams, whose world number one ranking is on the line if she fails to win the tournament. She added that her elder sister's late-career renaissance was an inspiration.
"She's winning, she's doing so well and I can do better. We always motivate each other. I'm so proud of her and we're so excited."
Venus rallied from behind to defeat Camila Giorgi of Italy 4-6, 7-6 (7/3), 6-1 to make the second week of a Grand Slam for the first time since Wimbledon 2011.
Azarenka, the champion in 2012 and 2013 who is unseeded this year after an injury-marred 2014, continued her impressive comeback, downing Czech 25th seed Barbora Zahlavova Strycova.
"There are things that obviously I want to improve. But it's progress. It's one step closer," said the Belarussian after her 6-4, 6-4 win. She next plays last year's beaten finalist Dominika Cibulkova.