By JOHN PYE
AP Sports Writer
MELBOURNE, Australia — A shirtless Rafael Nadal looks over his shoulder in the black-and-white photo, his biceps flexed and muscles rippling.
Nadal might be one step closer to his vaunted Rafa Slam, but he's also an Armani model. The photo will appear in a campaign launch next month. First, however, there's some tennis at hand, and Nadal is doing just fine as an advertisement for his sport.
He improved his winning streak to 25 matches in Grand Slam events Monday, beating No. 15 Marin Cilic 6-2, 6-4, 6-3 in the fourth round at the Australian Open.
Nadal already holds the French, Wimbledon and U.S. Open crowns and hasn't lost in a major since the last year's quarterfinals at Melbourne Park. Nobody has held all four men's majors at once since Rod Laver in a calendar year in 1969.
Nadal's victory sets up a quarterfinal against fellow Spaniard David Ferrer, who fended off big-serving 20-year-old Canadian qualifier Milos Raonic 4-6, 6-2, 6-3, 6-4.
In the previous round, Nadal had complained that a virus left him weak and caused him to sweat more than usual. He frequently peeled off his red shirt, often long after the soaked garment started clinging to his body.
He picked up the illness in Qatar two weeks ago and lost 6 pounds. Suddenly, some wondered if he had enough energy for his Rafa Slam.
"I'm not sweating that much tonight, so I am very happy," Nadal told the crowd after the match. "The two other days I was sweating like crazy and I felt very tired when I played the match."
The cooler conditions — the temperature dropped into the low 60s — no doubt helped.
"Today was the first day that I felt perfect physically," Nadal said. "So that is the most important thing."
That's probably not joyous news for No. 7 Ferrer. Andy Murray, who beat an injured Nadal in the Australian quarterfinals last year en route to his loss in the final to Roger Federer, would no doubt have noticed, too.
Murray found his rhythm early and made only 10 unforced errors in a 6-3, 6-1, 6-1 win over No. 11 Jurgen Melzer. In the quarterfinals, he'll meet Alexandr Dolgopolov, who ousted French Open finalist Robin Soderling 1-6, 6-3, 6-1, 4-6, 6-2.
Murray was confident when he said he was playing as well as he did this time last year. But, he added for good measure: "I don't want to get carried away. I've never won one of these things before." No British man has won a major since 1936.
In the night's last match, Kim Clijsters wasted plenty of chances to break Ekaterina Makarova before winning 7-6 (3), 6-2.
She had two set points on Makarova's serve in the 12th game, but couldn't convert and it went to a tiebreaker. He conversion rate in that set was one of seven.
In the first game of the second set, Clijsters had triple break point but again couldn't cash in. Her conversion rate at that point was one of 10.
She held and broke for a 2-1 lead, then received an anti-inflammatory medication from the trainer for pain in her left hamstring. It seemed to cure her quickly.
Two of Clijsters' three Grand Slam titles have come at the U.S. Open since she returned to the tour after a career break to get married and have a baby. Her win in New York in 2009, only a few tournaments back, made her the first mother to win a major since Evonne Goolagong Cawley at Wimbledon in 1980.
She worked with her clothing sponsor to make a green dress for this tournament in tribute to Goolagong Cawley. The Belgian was wearing it Monday night when the Australian great was in the VIP area at Rod Laver Arena to watch her. There wouldn't have been room in the players' box, with Clijsters' support crew at capacity.
"I probably have the fullest box that I travel with," she said. "I'm not doing everything. I'm not superwoman. We travel with a nanny — it keeps my mind focused when I have to be focused on tennis."
No. 2 Vera Zvonareva kept rolling toward a possible third consecutive Grand Slam final with a 6-4, 6-1 win over Iveta Benesova.
Zvonareva, who lost the Wimbledon final to Serena Williams and the U.S. Open final to Clijsters last year, moved into a quarterfinal against No. 25 Petra Kvitova, who rallied past No. 22 Flavia Pennetta 3-6, 6-3, 6-3.
No. 12 Agnieszka Radwanska beat China's Peng Shuai 7-5, 3-6, 7-5 and in the quarters will meet Clijsters, who seems in good position to take the title.
"I never thought things would be going well so soon after I started again," she said.
Defending champion Roger Federer takes on No. 19 Stanislas Wawrinka in the first all-Swiss quarterfinal at a Grand Slam. Federer is 6-1 against his sometimes Davis Cup teammate, who beat Andy Roddick to reach the quarters at a major for the third time. Federer matched Jimmy Connors' record when he reached his 27th consecutive quarterfinal at a major.
No. 3 Novak Djokovic, the 2008 Australian champion, takes on No. 6 Tomas Berdych. Berdych's straight-sets victory over Djokovic in last year's semifinals at Wimbledon is his only win in their five head-to-heads.
In the women's quarterfinals, No. 1 Caroline Wozniacki faces French Open champion Francesca Schiavone and China's Li Na is attempting to make back-to-back Australian Open semifinals when she plays No. 30 Andrea Petkovic.
Wozniacki is the youngest of the quarterfinalists at 20, while Schiavone is the oldest at 30. And she's coming off a 4-hour, 44-minute fourth-round win over Svetlana Kuznetsova, the longest women's Grand Slam match in the Open era.
After his night match on Monday, Nadal was quizzed on his modeling work and the 2011 underwear campaign. He's not comfortable talking about his chiseled frame, but admits he gets a kick out of it when others notice. Women were whistling when he took off his shirt Monday, taking pictures and yelling out declarations of love.
"I heard everything, but is nice," he said. "That's a very good feeling."