Maria Sharapova takes down the defending Australian Open champion, Caroline Wozniacki, to advance to the 4th round. (1:13)

MELBOURNE, Australia -- Maria Sharapova smacked a forehand winner -- the sort she has hit so many times, at so many key moments, over the years -- to take control against defending champion Caroline Wozniacki at the Australian Open. Sharapova balled up her fists, shut her eyes, threw back her head and let out a yell.

She showed she's ready to be a Grand Slam factor once again.

Sharapova, 31, grabbed the last four games to eliminate Wozniacki 6-4, 4-6, 6-3 in two-plus hours Friday and reach the fourth round at Melbourne Park, building the statement-making victory with aggressive groundstrokes that gave her a 37-10 edge in total winners.

"I haven't played many matches in the last year, especially against top players," Sharapova said. "And these are the kinds of matches I train for."

She cut her 2018 season short in September because of problems with her surgically repaired right shoulder.

Sharapova is seeded only 30th at Melbourne Park, where she won the 2008 title for one of her five Grand Slam trophies but hasn't been past the quarterfinals since 2015.

Sharapova missed the tournament in 2017 during a 15-month doping suspension that was triggered by a positive doping test during the previous year's Australian Open.

Wozniacki was the No. 3 seed in Australia, a year after beating Simona Halep in the final to claim her first major championship.

Next for Sharapova is a matchup against Australia's Ashleigh Barty, who beat Maria Sakkari 7-5, 6-1 to equal her best showing at any major tournament.

"I know it's going to be a tough crowd," Sharapova said.

No. 15-seeded Barty took two nearly years off from the tennis tour after the 2014 US Open and played cricket during that time.

"Her story is phenomenal," Sharapova said. "I know she took a little break and came back and just resurged."

Against Wozniacki, Sharapova hung in there in a back-and-forth contest.

Wozniacki led 3-2 in the third set after holding at love. But Sharapova finally gained the upper hand with a break for a 4-3 lead, clinched with that big forehand she was so excited about.

After holding to go up 5-3, Sharapova broke yet again to end it, closing with a big crosscourt backhand.

"The level was quite high," Sharapaova said. "I knew I was going to get a tough match."

In other women's matches Friday, 17-year-old American Amanda Anisimova showed why there are those who consider her a possible future star, producing one spectacular shot after another to upset 11th-seeded Aryna Sabalenka of Belarus 6-3, 6-2 and reach the fourth round.

Anisimova is the youngest American to get this far at Melbourne Park since Jennifer Capriati in 1993, and at any Grand Slam tournament since Serena Williams at the 1998 French Open.

"This is an unreal feeling," Anisimova said in an on-court interview. "I can't believe that this is happening right now."

Anisimova's first trip to Australia, and third appearance at a major tournament, now progresses to Week 2 and a matchup against two-time Wimbledon champion Petra Kvitova, who defeated Belinda Bencic 6-1, 6-4 on Friday night.

Also Friday, No. 5 Sloane Stephens survived two tough tiebreak sets to beat No. 31 Petra Martic 7-6, 7-6.

Stephens moves on to face Anastasia Pavlyuchenkova of Russia, who defeated Aliaksandra Sasnovich 6-0, 6-3 earlier in the day.

Second-seeded Angelique Kerber celebrated her birthday by dropping just one game against No. 240-ranked wild-card entry Kimberly Birrell.

Kerber, who won Grand Slam titles in 2016 in Australia and the US Open and again at Wimbledon last year, beat Birrell 6-1, 6-0 on the day she turned 31.

"I always enjoy my birthday here -- I think it's the 12th time in a row," Kerber said. "I'll never forget the birthdays here in Australia."

The crowd sang "Happy Birthday" as she left the court. Kerber moved into a fourth-round match against American Danielle Collins, who beat No. 19-seeded Caroline Garcia 6-3, 6-2.

The Associated Press contributed to this report.