The "Rafa Slam" is still alive after Rafael Nadal beat Marin Cilic 6-2, 6-4, 6-3 at the Australian Open on Monday to maintain his chance of owning all four Grand Slam trophies at once.

That's a feat that hasn't been achieved since Rod Laver won four majors in a calendar year in 1969.

Playing on Melbourne Park's center court that is named for the Australian great, Nadal advanced to a quarterfinal against Spain's David Ferrer. Nadal is attempting to add to the Grand Slam titles he won last year at the French Open, Wimbledon and the U.S. Open.

Kim Clijsters, seeded No. 3 and increasingly looking as if she can add to her U.S. Open crown, also reached the quarterfinals with a 7-6 (3), 6-2 victory over Ekaterina Makarova of Russia. No. 2 Vera Zvonareva advanced as well.

Clijsters is in the second full season of a comeback after 2½ years in retirement. She won five singles titles and the U.S. Open last year.

"I never thought things would be going well so soon after I started again," she said.

In other fourth-round matches, Alexandr Dolgopolov upset No. 4 Robin Soderling, the highest of the seeded players knocked out of the men's draw. No. 5 Andy Murray defeated No. 11 Jurgen Melzer, and No. 7 Ferrer defeated Canadian qualifier Milos Raonic.

Nadal hasn't dropped a set through four rounds despite a lingering virus he picked up two weeks ago in Qatar.

"Before the match I was a little bit nervous," Nadal said. "I know how aggressive he can play. I think I played my best match this year here at the Australian Open."

At Nadal's previous match, he sweated profusely while playing Saturday night. On Monday, the weather was cooler and his condition clearly was improving.

"I'm not sweating that much tonight," Nadal said. "The two other days I was sweating like crazy and I felt very tired when I played the match. Today was the first day I felt perfect physically."

A capacity crowd of 15,000 that included country music star Kenny Rogers — sitting next to seven-time Grand Slam singles winner Evonne Goolagong Cawley — saw Nadal struggle at times on his serve.

The fourth game went to deuce four times, but Nadal finally prevailed on his service with a forehand smash at the net, followed shortly by his patented "Vamos" as he walked to the back of the court.

In the next game, he set up one of four break points with an amazing get of Cilic's drop shot at the net, sending it across the court to the side line for a winner. He converted for 4-1 and, after serving a double-fault on his first set point, Nadal took the opening set when Cilic netted a backhand.

Nadal went ahead 4-3 on a service break in the second set, then clinched it when Cilic, who beat American John Isner in five sets Saturday, hit a forehand long. He advanced when Cilic double-faulted on match point.

"It's tough to say. From this match, I didn't push him too much," Cilic said when asked to gauge Nadal's game. "You couldn't see how much does he have in the tank and, I mean, especially as I didn't play great. But definitely he's got good confidence."

Earlier, Murray also advanced to the quarterfinals, setting up a possible semifinal with Nadal.

"I don't want to get carried away," Murray said after his 6-3, 6-1, 6-1 win over Melzer of Austria. "I've never won one of these things before."

The win put Murray closer to a second straight appearance in the final at Melbourne Park, where he lost to Roger Federer last year after beating Nadal in the quarterfinals.

He also came close to ending a woeful British streak — no male winner of a Grand Slam since Fred Perry in 1936 — at the 2008 U.S. Open, where he lost final to Federer.

Before Murray gets a potential crack at Nadal, he'll face an unexpected quarterfinal rival after Dolgopolov dropped Soderling 1-6, 6-3, 6-1, 4-6, 6-2, ending the French Open finalist's eight-match winning streak.

"He's got a very unorthodox game, very different to most of the guys on the tour," Murray said of his Ukrainian opponent. "He has a game that can make you play strange shots or not play that well."

Dolgopolov said his father, Oleksandar, worked as a coach for the likes of Andrei Medvedev, so he sometimes hit with the players when they were practicing and the family was on tour.

"For sure I had some good times. I was a bit maybe annoying for some players to play with me," he said. "It was nice to start a tennis career like that."

Ferrer set up an all-Spanish quarterfinal against Nadal with his 4-6, 6-2, 6-3, 6-4 win over 20-year-old Raonic, who upset No. 10 Mikhail Youzhny in the third round.

Soderling hadn't dropped a set during his surge that started with his run to the title at the Brisbane tuneup. He dominated the opening set but couldn't keep it up against Dolgopolov, who is making his fourth appearance in a major and was coming off a five-set win over former Australian Open finalist Jo-Wilfried Tsonga.

Dolgopolov's cross-court backhand to bring up his first match point was typical of the 50 winners he hit against a stunned Soderling. Soderling saved three match points, but his run came to an end with another unforced error, his 51st.

Clijsters held two set points in the 12th game of the opening set on Makarova's service that the Russian player fended off. Clijsters converted just one of 10 break-point chances in the set.

When it went to a tiebreaker, Clijsters' experience came through. The Belgian won the set when Makarova hit a forehand wide.

Clijsters called for the trainer after the third game of the second set and took one or two tablets, then asked how long it would be before the medication took effect. The trainer indicated about 20 minutes, and Clijsters finished the match in slightly over that time frame.

No. 12 Agnieszka Radwanska beat China's Peng Shuai 7-5, 3-6, 7-5 and will meet Clijsters in the quarters.

Zvonareva is rolling toward a third consecutive Grand Slam final with a 6-4, 6-1 win over Iveta Benesova. Zvonareva moved into a quarterfinal against No. 25 Petra Kvitova, who rallied past No. 22 Flavia Pennetta 3-6, 6-3, 6-3.

Zvonareva said she ignores those who say she doesn't deserve her ranking because she hasn't won a major.

"There are a lot of people that always underestimated me and ... and there are a lot of people that thought I never will make it to even like Grand Slam semifinals or something," she said. "But it doesn't really matter to me ... the most important thing is that I believe in myself."