MELBOURNE, Australia (AP) — On paper, Serena Williams' second-round match on Thursday against Lucie Safarova should be no contest.

The six-time Australian Open champion in search of her record 23rd Grand Slam singles title has beaten the Czech player all nine times they've met, including the 2015 French Open final.

But Safarova, ranked 61st, saved nine match points in the second set of her first-round match here against Yanina Wickmayer before advancing 3-6, 7-6 (7), 6-1.

So Williams may need to be patient, or ruthless, in the match which opens night play at Rod Laver Arena.

After her win Tuesday, Safarova wasn't aware of the extent of her feat.

"I stopped counting after a few (match points), I was like, just another one," she said. "But I was like, 'I'm just going to go for it and if she closes the match, well OK, but I'm just going to play my game.' It was exciting."

Safarova is expecting a fast start from Williams.

"Serena's always a tough opponent," Safarova said. "She hasn't played many matches so that could be maybe a little bit to my advantage, but she always comes out strong. I have nothing to lose so I'll be ready."

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Here is a look at some other matches in the bottom half of the draw on Thursday, the fourth day of the Australian Open:

CONCERN FROM RAONIC: Milos Raonic takes on Gilles Muller, who is coming off his first career tournament victory at the Sydney International last week. Muller broke down at the trophy presentations in Sydney, relieved that he finally achieved a win.

Raonic lost to Muller in Valencia, Spain in 2012, although that was before Raonic developed into the third-ranked player in the world. Raonic also had to retire from a second-round match at Wimbledon in 2011 while leading 3-2 in the first set due to a right hip injury. "I have struggled with him," Raonic said. "He had a great, phenomenal week last week. For him it was something very special, and obviously it was pretty special to see, as well, that final and his reaction to it." They play an afternoon match on Margaret Court Arena.

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MUTUAL RESPECT: Johanna Konta beat Naomi Osaka in straight sets in their only previous meeting in the semifinals of qualifying at the U.S. Open in 2015. The pair, who meet again Thursday — the opening match of the day at Rod Laver — made positive impressions on each other during that match in New York. "I remember playing her, and she had a real good serve and a really good return," Osaka said of last year's semifinalist. "I think it's really awesome like how she rose so high and quickly. She's a really good player." Konta returned the favor: "She's improved a lot. I know she plays a big game. She has big shots. I'm definitely prepared to go in for a battle."

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DOMINATING DJOKOVIC: Six-time champion Novak Djokovic has beaten his second-round opponent, Dennis Istoman, all five times they have met. Two of those matches have come at the Australian Open, although it wasn't until the third round. Istoman has won only one set in those five career matches.

Among other matches Thursday, 2009 champion Rafael Nadal plays 2006 finalist Marcos Baghdatis and No. 3-seeded Agnieszka Radwanska takes on Mirjana Lucic-Baroni.