Roundup: Serena and Venus Williams record comeback wins at the Australian Open

World No.1 Serena Williams overcame a first-set scare from the plucky Elina Svitolina to advance to the fourth round of the Australian Open on Saturday.

Despite losing the first set and being forced into several grinding rallies, Williams eventually withheld the threat of her Ukrainian opponent and eased through to the next round with a 4-6, 6-2, 6-0 victory.

The three-set win means a potential semifinal with her elder sister remains possible, after Venus Williams also survived losing the first set to account for Italian Camila Giorgi.

On the men's side, reigning champion Stanislas Wawrinka barely broke sweat in defeating Jarkko Nieminen, while imposing Canadian Milos Raonic continued to find form with a comfortable straight sets win over Benjamin Becker.

On center court, despite losing two of her first three service games, Serena Williams battled to a hard fought victory over 26th-seed Svitolina.

The Ukrainian had set the agenda in the match, breaking Serena in the first game and cruising to a first-set win. However, it subsequently sparked the world No.1 into life.

After taking the match to a deciding set, Serena saved two break-point opportunities early in the third, pumping her fist in the direction of her coach's box after eventually holding serve.

From that moment on, she was unstoppable, claiming the third set 6-0 to set up a fourth-round tie with Garbine Muguruza, who she lost to at last year's French Open.

"It was a good loss," Serena said after the match, when recalling last year's defeat. "As angry as I was, it was the best loss I had the whole of last year.

"That one in particular made me realize what I needed to work on. It opened my eyes towards a lot of things. I was like 'oh my god, if I don't change, then I'm going to be forever in the same position'.

"It actually ended up helping me a lot."

Her sister Venus also progressed with a 4-6, 7-6 (7-3), 6-1 win over Giorgi.

The Italian had served for the match at 5-3 in the second, only for Venus to gallantly fight back and break in four of Giorgi's next six service games.

On the men's side, Wawrinka hit 55 winners to 18 to easily see off the threat of Niemenen on Rod Laver Arena with 6-4, 6-2, 6-4 win.

Speaking after the match, Wawrinka refused to suggest the pressure that comes with his position as reigning champion could become a hindrance, saying 2014's triumph is well and truly in the past.

"I don't try to think or compare anything," Wawrinka told reporters after his match. "For me, it's a new tournament.

"It's been going well, I'm playing great tennis, that's it. I'm focused match after match. That's what is important.

"I had some amazing memories from last year, for sure. But it's really important to stay on what's happening today and what's going to happen tomorrow."

World No. 8 Raonic was also hardly troubled as he defeated Becker 6-4, 6-3, 6-3.

It continued the Canadian's run of three consecutive straight sets victories at this year's Australian Open. However, he is yet to pass the fourth round of the competition in four attempts and will have to beat 12th seed Feliciano Lopez to break that trend.

Lopez had earlier been forced to navigate two tiebreakers in order to defeat Jerzy Janowicz 7-6 (8-6), 6-4, 7-6 (7-3).

Meanwhile, in the women's draw, two-time Australian Open winner Victoria Azarenka continued her comeback from injury with a 6-4, 6-4 win over 25th seed Barbora Zahlavova-Strycova.

Earlier in the day, No. 6 seed Agnieszka Radwanska recorded a comfortable 6-0, 7-5 win over American Varvara Lepchenko, while world No.11 Dominika Cibulkova won 10 of the last 12 service games to defeat Alize Cornet 7-5, 6-2. Endit