Rafael Nadal had to wait while Caroline Wozniacki saved two match points and worked her way back into the Australian Open in the preceding match on Rod Laver Arena.

Nadal, the 2017 runner-up, wasted no time in reaching the third round, dropping only one service game - while serving for the match - and making just 10 unforced errors in a 6-3, 6-4, 7-6 (4) win over Leonardo Mayer on Wednesday.

''It's an important victory for me, I mean, he's a tough opponent. Leonardo is a player with big potential,'' said Nadal, who won the French and U.S. Opens last year but had his preparation for Australia delayed because of an injured right knee. ''After a while without being on the competition ... second victory in a row, that's very important.''

There was more drama earlier on the center court and Margaret Court Arena, when second-seeded Wozniacki and 2008 runner-up Jo-Wilfried Tsonga had to come back from big deficits.

Wozniacki was 5-1 down and facing two match points in third set against No. 119-ranked Jana Fett before deciding she had no choice but to attack.

''That was crazy,'' Wozniacki said after winning the last six games in a memorable 3-6, 6-2, 7-5 victory. ''I don't know how I got back into the match. I was like, 'This is my last chance.

''At 5-1, 40-15, I felt like I was one foot out of the tournament. She served a great serve down the T - it was just slightly out. I was kind of lucky.''

Wozniacki won the next nine points, and 24 of the 31 points played from when she first faced match point. She clinched a 75-minute third set on her first match point when Fett netted a backhand.

The former No. 1-ranked Wozniacki will next play No. 30 Kiki Bertens, who beat Nicole Gibbs 7-6 (3), 6-0.

Tsonga rallied from 5-2 in the fifth to overcome Denis Shapovalov 3-6, 6-3, 1-6, 7-6 (4), 7-5 in a 3-hour, 37-minute match that contained one of his nonchalant between-the-legs shots on an important point. And 38-year-old Ivo Karlovic overcame Yuichi Sugita 7-6 (3), 6-7 (3), 7-5, 4-6, 12-10.

Marta Kostyuk came from the other angle, the 15-year-old qualifier followed up her first-round win over 25th-seeded Peng Shuai with a 6-3, 7-5 victory over wild-card entry Olivia Rogowska.

The Australian Open junior champion last year, who entered the season-opening major ranked No. 521, Kostyuk became the youngest player since Martina Hingis in 1996 to win main draw matches at the season-opening major.

Things will get harder for her now, against fellow Ukrainian and No. 4-seeded Elina Svitolina, who had a 4-6, 6-2, 6-1 win over Katerina Siniakova.

Another Ukrainian, Kateryna Bondarenko, beat No. 15-seeded Anastasia Pavlyuchenkova 6-2, 6-3 and will next play No. 19 Magdalena Rybarikova.

Belinda Bencic had a letdown two days after upsetting Venus Williams, losing 6-1, 6-3 to Thai qualifier Luksika Kumkhum.

Bencic, who combined with Roger Federer to win the Hopman Cup for Switzerland earlier this month, saved three match points on her serve before netting a backhand to give No. 124th-ranked Kumkhum a spot in the third round for the first time.

''I tried to reset and focus on the next match,'' Bencic said. ''I think it was also a very tough second round, for me the toughest I could get.''

French Open winner Jelena Ostapenko struggled at times before beating Duan Yingying 6-3, 3-6, 6-4.

Among the seeded men advancing were No. 6 Marin Cilic, who beat Joao Sousa 6-1, 7-5, 6-2, and No. 10 Pablo Carreno Busta, who was leading 6-2, 3-0 when Gilles Simon retired from their second-round match with a thigh injury.

No. 23 Gilles Muller outlasted Malek Jaziri in five sets, Kyle Edmund had a straight-sets win over Denis Istomin - who beat then defending-champion Novak Djokovic in the second round here last year - and No. 28 Damir Dzumhur beat John Millman.

Ryan Harrison beat No. 31 Pablo Cuevas 6-4, 7-6 (5), 6-4.

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