MELBOURNE, Australia — Rafael Nadal beat sixth-seeded Gael Monfils in four sets today to reach the quarterfinals of a Grand Slam tournament for the 30th time, prompting talk of a potential Australian Open final against Roger Federer.

The veterans have a long way to go to get there.

For the 30-year-old Nadal, his first priority is against No. 3-seeded Milos Raonic.

With No. 1-ranked Andy Murray and No. 2 Novak Djokovic — the two most consistent performers in the last six years at Melbourne Park — upset in the first week, Wimbledon finalist Raonic is the highest-ranked player in the draw.

He advanced to the last eight here for third straight year with a 7-6 (6), 3-6, 6-4, 6-1 win over No. 13 Roberto Bautista Agut.

Nadal is the only major winner still in contention on the bottom half of the draw, although he hasn’t added to his tally of 14 majors since the capturing the French Open in 2014.

Federer, in the top half of the draw, plays Mischa Zverev on Tuesday, and would have to beat him and either Stan Wawrinka or Jo-Wilfried Tsonga — the other quarterfinalists playing Tuesday — to advance to the final.

Nadal’s 6-3, 6-3, 4-6, 6-4 win over U.S. Open semifinalist Monfils in the fourth round was his first over a top 10 player at a Grand Slam since that run to his last title at Roland Garros. It also ended a four-match streak against top 10 players.

“Being in the quarterfinals of a Grand Slam after couple of years not being there is very special for me,” said Nadal, who last progressed this far at the 2015 French Open.

It also showed that after a couple of months off to rest his injured left-wrist, he is still a contender at the majors. He hasn’t won an Australian title since 2009.

In the other quarter, No. 15 Grigor Dimitrov closed with an ace to hold off No. 117 wild-card entry Denis Istomin 2-6, 7-6 (2), 6-2, 6-1. Istomin, who upset six-time champion Novak Djokovic in the second round, needed repeated treatment on his tiring legs in the third and fourth sets.

Serena Williams kept her bid for an Open-era record 23rd major title on track with a 7-5, 6-4 win over No. 16-seeded Barbora Strycova to reach the quarterfinals here for the 11th time.

Despite four service breaks — two in the first four games — and 46 unforced errors, and with the fluky net cord and the off-balance, scrunched-shouldered backhand that bounced flatly and clinched her the first set on her eighth set point, she ground down Strycova.

“It’s good to know I have a Plan B, or Option 2. I wasn’t serving my greatest today, also she was putting a lot of returns in there,” said Williams.