Serena in charge as Djokovic races past Tsonga

Serena Williams on Thursday stepped up her drive for a record-equalling 24th Grand Slam by swatting aside Eugenie Bouchard, as world No 1 Novak Djokovic won an emotional 2008 Australian Open final rematch with Jo-Wilfried Tsonga.

But women's top seed Simona Halep and young gun Alexander Zverev had to dig deep to make the third round on a day of epic battles and the latest start to a match ever at the tournament.

American great Williams followed up her first round 49-minute romp by spending just 70 minutes on Rod Laver Arena to dispose of the Canadian 6-2, 6-2.

"It wasn't an easy match tonight," said the 37-year-old, seeded just 16.

"So I knew 'Serena, you've got to come out hot, you've got to come out firing, she's a really good player and I haven't had many matches since last year'."

Williams is bidding to match Margaret Court's record of 24 Grand Slam crowns, and win an eighth in Australia, on her first return to Melbourne Park since lifting the trophy in 2017 while pregnant.

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Serbian top seed Djokovic is also looking to make history by winning a seventh title.

He was too good again for France's Tsonga, who he beat in the 2008 final, rolling through 6-3, 7-5, 6-4.

"You could feel the tension on court at the beginning. We felt a lot of emotion and tried to play a great game," said Djokovic as the memories of that tense final came flooding back.

In contrast, world No 1 Halep staggered through against American Sofia Kenin 6-3, 6-7 (5/7), 6-4 – her second three-set test in a row.

"I have no idea how I won this, it's so tough to explain what happened on court," said the French Open champion, who now meets Venus Williams after the 38-year-old rolled back the years to beat France's Alize Cornet.

In another titanic battle, Canadian Milos Raonic ousted 2014 champion Stanislas Wawrinka in four tightly-contested sets that all went to tie-breaks, while eighth seed Kei Nishikori was stretched to a draining five sets against Ivo Karlovic.

Seventh seed Dominic Thiem limped out when he retired while losing 7-5, 6-4, 2-0 to young Australian wildcard Alexei Popyrin.

Zverev, hailed as a flag-bearer for the next generation, also struggled against veteran world number 36 Jeremy Chardy, before putting him away 7-6 (7/5), 6-4, 5-7, 6-7 (6/8), 6-1.

NIGHT OWL MUGURUZA WINS RECORD AUSSIE OPEN LATE SHOW

Two-time Grand Slam winner Garbine Muguruza emerged triumphant in the latest women's match ever held at the Australian Open after defeating Briton Johanna Konta in the early hours of Friday morning.

Muguruza and Konta's match on Margaret Court Arena did not start until 12:30 am Friday morning -- a record at the season-opening Grand Slam -- and finished with a 6-4, 6-7 (3/7), 7-5 victory for the Spaniard two hours and 42 minutes later at 3:12am.

"I'll go get some breakfast now," Muguruza joked after wrapping up the win to set up a third-round clash with Timea Bacsinszky of Switzerland.

The previous record for the latest start was set last year when a second-round match between Daria Gavrilova and Elise Mertens began at 11:59pm.

The latest end to a match at any Grand Slam was also at Melbourne Park in 2008, when Lleyton Hewitt and Marcos Baghdatis finished a five-setter at 4:34am.

Karolina Pliskova complained about the scheduling last year when her fourth-round match started at 11pm and finished almost three hours later, giving her barely 10 hours before she had to back up against world number one Simona Halep.

The schedule is largely determined by local television demands to play high-profile matches in the evening prime time.

Despite the hour, both Muguruza and Konta made a contest of their late-night encounter, which was watched live by only a few die-hard spectators.

US Open champion and fourth seed Naomi Osaka, meanwhile, had it relatively easy, sweeping past Slovenia's Tamara Zidansek 6-2, 6-4 with the roof closed on Margaret Court Arena due to the rain.

The 21-year-old's breakthrough at Flushing Meadow over Serena Williams last year made her a new standard bearer for tennis in her Japanese homeland and Asia, and she is working hard on living up to the hype.

"I thought I served alright, this was my first time playing her and I'm just happy to win to be honest," Osaka said after setting up a clash with Taiwan's Hsieh Su-wei.

In contrast, Asia's top-ranked men's player Nishikori needed an energy-sapping 3hr 48min to get past big-serving Croat Karlovic 6-3, 7-6 (8/6), 5-7, 5-7, 7-6 (10/7) in humid conditions.

Sixteenth seed Raonic emerged the victor against Wawrinka, a three-time Grand Slam champion who is on the comeback trail from injury.

The Swiss, unseeded for the first time since his debut in 2006, fell 6-7 (4/7), 7-6 (8/6), 7-6 (13/11), 7-6 (7/5).

Despite being seeded six and seven respectively, neither Elina Svitolina or Karolina Pliskova has progressed further than the last eight at the Australian Open.

But self-assured Svitolina is bubbling with confidence after dismantling Viktoria Kuzmova 6-4, 6-1, while Pliskova woke up after losing the first set to race past Madison Brengle 4-6, 6-1, 6-0.

Other women through included Italy's Camila Giorgi and China's impressive Wang Qiang. Men still in the hunt included Croat Borna Coric and Spain's Pablo Carreno-Busta.