Rafael Nadal drops set to Karen Khachanov before advancing to fourth round of Australian Open

Berrettini survives five-set thriller against Alcaraz at Australian Open (0:49)

Matteo Berrettini advances to the Australian Open fourth round after a five-set thriller against Carlos Alcaraz. (0:49)

Rafael Nadal has advanced to the fourth round of the Australian Open with a 6-3, 6-2, 3-6, 6-1 victory over No. 28-seeded Karen Khachanov.

Nadal, aiming for a men's record 21st Grand Slam singles title, was facing his first seeded opponent and dropped his first set of the tournament.

The sixth-seeded Nadal struggled in the third set Friday when the 6-foot-6 Russian broke to go up 3-1 before taking the set in 57 minutes at Rod Laver Arena in Melbourne.

But the 35-year-old Nadal quickly regained control in a dominant fourth set, twice breaking the Olympic silver medalist.

Nadal shares the men's record of 20 singles titles with Roger Federer and Novak Djokovic.

Djokovic, a nine-time champion at Melbourne Park, couldn't play after having his visa canceled for failing to meet Australia's strict COVID-19 vaccination regulations. Federer is skipping the Australian Open while he continues his recovery from injury.

Wimbledon runner-up Matteo Berrettini fended off 18-year-old Spanish player Carlos Alcaraz 6-2, 7-6 (3), 4-6, 2-6, 7-6 (5) on Friday to reach the fourth round.

The seventh-seeded Berrettini wasted a match point when Alcaraz was serving to force a fifth-set tiebreaker, netting a return to a second serve.

But the 25-year-old Italian player dominated the match's super tiebreaker, taking a 9-5 lead to get four more match points before the No. 31-ranked Alcaraz finished with a double fault.

"He's unbelievable. At his age, I didn't even have an ATP point,'' Berrettini said. "He's impressive. He'll only improve, playing matches like this. He's showed everyone his potential."

Berrettini advanced to the fourth round at Melbourne Park for the second straight year and for the eighth time at a Grand Slam event, equaling Fabio Fognini and Adriano Panatta's Open-era record for the most by an Italian man.

Also on the men's side, Olympic gold medalist Alexander Zverev advanced to the fourth round with a 6-3, 6-4, 6-4 win over Radu Albot, the No. 124-ranked qualifier from Moldova.

The third-seeded Zverev finished it off with his third match point in just under two hours. He converted three of his six break-point chances and fended off all five on his own serve.

Zverev hit 44 winners and 16 aces to prepare for his next match against No. 14-ranked Denis Shapovalov of Canada, who beat No. 23 Reilly Opelka 7-6 (4), 4-6, 6-3, 6-4 in another men's third-round match.

Miomir Kecmanovic is making the most of the absence of his fellow Serbian Djokovic, reaching the fourth round at a major for the first time with a 6-4, 6-7 (8), 6-2, 7-5 win over No. 25-seeded Lorenzo Sonego.

He had been drawn to play the top-ranked Djokovic in the first round. Kecmanovic instead faced Salvatore Caruso -- a so-called lucky loser from qualifying -- in the first round and Tommy Paul in the second.

Kecmanovic will next play 17th-seeded Gael Monfils, who beat No. 16 Cristian Garin 7-6 (4), 6-1, 6-3.

The Associated Press contributed to this report.