Australian Open, Day 4 Wrap: Sluggish Serena Joins Rampant Djokovic in Round Three

Serena Williams was slow to get going before finding her groove to bulldoze Vera Zvonareva and join rampant fellow world number one Novak Djokovic in the Australian Open third round Thursday.

With the temperatures again sizzling around 33 Celsius (93 Fahrenheit) at Melbourne Park, the American 18-time Grand Slam champion took time to adjust to the sauna-like conditions against the Russian veteran.

She had to save two set points before exploding into action in the second set to easily win 7-5, 6-0 and keep alive her dream of a sixth Australian title.

Djokovic, gunning to be crowned champion a fifth time, was on fire in his showdown against Andrey Kuznetsov, crushing the hapless Russian 6-0, 6-1, 6-4, while defending champion Stan Wawrinka had to work hard to get past Marius Copil.

The Romanian took the fourth seed to two tiebreakers before the Swiss star triumphed 7-6 (7/4), 7-6 (7/4), 6-3. Japan's Kei Nishikori also went through.

Williams said she only started finding her range when she relaxed.

"She started out really well, she was really aggressive and I was a little too passive," said Williams, the top seed.

"Once I got down I thought 'Serena, you've done so well here you've got nothing to lose, just have fun and enjoy yourself' -- then I started to play a lot better."

While the old guard of Williams and Maria Sharapova are safely into the third round, the new generation of Eugenie Bouchard and Simona Halep have looked more impressive in the early rounds.

Sixth seed Agnieszka Radwanska is also in ominous form after hiring former great Martina Navratilova as her coach.

The Pole, a semi-finalist last year, took just 44 minutes to brush aside Sweden's Johanna Larsson 6-0, 6-1 and has only lost four games in two matches.

"She's helped me a lot, on and off the court," Radwanska said of Navratilova. "We're working on a couple of things right now."

Williams faces a tricky third round match against another of the new young guns in Spanish world number 24 Garbine Muguruza, who beat Daniela Hantuchova 6-1, 0-6, 6-1.

Serena's sister Venus also progressed with the seven-time Grand Slam champion in vintage form to blast past fellow American Lauren Davis 6-2, 6-3, while Czech fourth seed Petra Kvitova swept aside German Mona Barthel in straight sets.

Rampant leader! Novak Djokovic cruised his way into the third round in Australian Open.

© AFP

- The perfect game -

Top seed Djokovic came out of the blocks firing against Kuznetsov, who had no answer to his booming serve and powerful and effortless groundstrokes in a masterclass performance.

"Overall I executed the game plan," said the Serb.

"Everything I intended to do, almost 100 percent, from every second in my game, serve, baseline play, aggressive shots and aggressive returns."

In contrast Wawrinka, who beat Rafael Nadal in last year's final, was put through his paces by Copil and was glad to get off court after three sets.

"The court was quite fast and he was really aggressive on serve and I was happy to get through in three sets," said Wawrinka.

Fifth seed Nishikori was forced to four sets by Croatia's Ivan Dodig, digging deep to keep his dream of a maiden major title alive with a 4-6, 7-5, 6-2, 7-6 (7/0) win in front of a noisy pro-Japanese crowd.

"It was very warm conditions today and he was playing really well, very aggressive, good returns and it was a tough battle," Nishikori said.

Others through included Spanish 12th seed Feliciano Lopez and American 19th seed John Isner.

The blockbuster evening clash will see two-time champion Victoria Azarenka face off with close friend and former world number one Caroline Wozniacki.

Azarenka is ranked just 44 after an injury-marred 2014 while Wozniacki is seeded eight, with whoever wins on course to meet Serena Williams in the quarter-finals.

Wozniacki's best performance in Melbourne was reaching the 2011 semi-finals, while Azarenka won the title in 2012 and 2013.