MELBOURNE, Australia -- Five-time champion Serena Williams has now won more matches at the Australian Open than any other woman, notching career win No. 61 in scorching conditions Friday (Australia time) as she advanced to the fourth round with a 6-3, 6-3 victory over Daniela Hantuchova.

Williams converted her fourth match point on No. 31-seeded Hantuchova's serve to finish it off in 1 hour, 20 minutes, keeping her time on court to a minimum during the once-in-a-century heat wave gripping Melbourne. She has only dropped 12 games in three straight-set wins this week.

The No. 1-ranked Williams equaled Margaret Court's Australian Open mark of 60 wins with her second-round victory, and on Friday matched Lindsay Davenport's record of 69 main-draw matches here in the Open era.

That means she'll set another record just by showing up on Sunday, against the winner of the night match between 2011 U.S. Open champion Sam Stosur and former No. 1-ranked Ana Ivanovic.

The temperature hit 39 Celsius (102 Fahrenheit) during Williams' match and climbed to 40 C (104 F) later Friday.

"It was a tough match ... it's definitely hot, but you have to be ready to play," Williams said. "And then you have to prepare yourself mentally, too."

Williams has won 24 consecutive matches dating back to August, and she seems to be getting better with age.

"I feel like, in life 32 is young. In sports it's old," Williams said. "But for whatever reason, I feel like I just never was really able to reach my full potential, and I feel like recently I just have been able to do a little better. I just keep trying to improve on everything."

Williams was entered in the doubles with her sister but withdrew after her singles match Friday, citing a leg injury for Venus, which saved her from another match in the blazing heat in the afternoon.

"I love playing doubles, love playing with Venus, but sometimes it doesn't work out," she said. "I guess it's a relief, but we love to play doubles and we love to be out there ... so I'll definitely miss it."

No. 9 Angelique Kerber posted a 6-3, 6-4 win over American Alison Riske and said her main aim had been to "get off the court before it became really hot."

Two-time finalist Li Na broke Lucie Safarova in the second set when the Czech was serving for the match and came back for a 1-6, 7-6 (2), 6-3 win. Li had one simple request before answering questions in her on-court, post-match interview after battling for 2½ hours in the heat: "Can we stand in the shadow?"