Cilic looking to be next giant killer

MELBOURNE, Australia -- The two hottest players on the men's tour face off in the quarterfinals Tuesday, and they're not Roger and Rafa for a change. Andy Roddick, trying to end a seven-year Grand Slam drought, and Marin Cilic are each 9-0 this year. Could the young Croat be the latest surprise at the Australian Open?

Andy Roddick (7) versus Marin Cilic (14)

Head to head: 1-1

Cilic and Juan Martin del Potro often draw comparisons. They're both 6-foot-6 and possess similar baseline games as well as low-key personalities.

Del Potro gradually knocked off the big boys en route to the U.S. Open title last September, and Cilic is following the same road. The 21-year-old ousted Andy Murray in the fourth round of the U.S. Open in September and took care of del Potro in five sets on Sunday, avenging his loss at Flushing Meadows.

In between, Rafael Nadal, Nikolay Davydenko and Fernando Verdasco were Cilic's victims.

"Definitely the win against Murray in New York was very good, and then against Davydenko, Nadal and Verdasco," Bob Brett, Cilic's venerable coach, said before practice Monday. "He's just become more aggressive. Now he's stronger, fitter, and he's able to sustain it for a longer period of time. Playing these guys more often, it's possible to learn."

Cilic certainly isn't averse to learning, added Brett, who has coached a few other Croats, including zany Goran Ivanisevic and intelligent Mario Ancic. Brett has also coached Boris Becker. Cilic and Brett have been together for almost six years.

"What is very good about him is that he's always ready for that something that needs to be changed and added to," Brett said. "He's very receptive and listens to my craziness. He's so committed to being good. He's a great athlete, he wants to be at the top, so he does everything that goes with that. He really has the passion."

Cilic battled his way to the last eight, going the distance, surprisingly, against 17-year-old Aussie wild-card Bernard Tomic in the second round. Cilic had del Potro on the ropes at the U.S. Open but couldn't administer the knockout punch, with the Argentine returning the favor here. Up a set and holding a break point at 3-3, del Potro erred on a routine backhand. Then, he failed to serve out the third.

Roddick needed five to eliminate Fernando Gonzalez, rallying from a 2-1 set deficit for the first time since 2003. He wore down the Chilean, who must have thought the gods were against him given the close calls that went the American's way.

Roddick doesn't read too much into his 1-1 record against Cilic, because their last meeting was two years ago.

"He's just a tough player," Roddick told reporters. "One of those guys, 6-foot-6, 6-foot-7, just kills the ball from the baseline. He likes to play inside of the court, goes after the ball every point. He's relentless."

So is Roddick.

Prediction: Roddick in four.

Rafael Nadal (2) versus Andy Murray (5)

Head to head: Nadal leads 7-2

The last time they met at a Grand Slam two years ago, Murray edged Nadal in four sets in New York to reach his first, and only, major final. But the last time they faced off on hard courts, last year in Indian Wells, Calif., Nadal dropped only three games.

Darren Cahill, an analyst for ESPN and much-respected coach, doesn't like the matchup from Murray's perspective.

"You have to try to take time away from Rafa if you can, and that's not normally Andy's way of doing things, so Andy has to find another way to beat this guy," Cahill said. "He has to go outside his comfort zone a little bit. If Rafa is playing at his best, that's a huge challenge and obstacle for Andy to get over. The ball kicks up in Indian Wells, and it certainly kicks up here."

Both have looked sharp. Murray, armed with a favorable draw, hasn't lost a set, while Nadal warmed up nicely by defeating talented Philipp Kohlschreiber and 6-foot-10 Croatian Ivo Karlovic.

Prediction: Nadal in four.

Justine Henin versus Nadia Petrova (19)

Head to head: Henin leads 12-2

The bottom half of the women's draw is truly crazy. Petrova, Zheng Jie and Maria Kirilenko join Henin. We all expected Henin to meet U.S. Open champion Kim Clijsters, although Petrova got in the way.

The towering Russian initiated a little controversy Sunday when she indicated that Clijsters didn't give her enough credit.

"It was a very good match from my side, and it would be really nice to get good feedback from the person that I defeated," Petrova told reporters.

Petrova, owner of a huge game that can trouble anyone, went on to beat two-time Grand Slam champion Svetlana Kuznetsova, who did praise her. Petrova's head-to-head record against Clijsters and Kuznetsova prior to Melbourne was 1-9.

Henin has shown a champion's heart in grueling wins over Elena Dementieva, Alisa Kleybanova and Yanina Wickmayer. She could have lost all three.

Prediction: Petrova in three.

Zheng Jie versus Maria Kirilenko

Head to head: Zheng leads 4-1

Kirilenko already got what she wanted, despite not yet winning the tournament or even reaching the final.

"When I was a kid, I had a dream to be in a Grand Slam main draw in Australia when I have a birthday," Kirilenko, who turned 23 Monday, told reporters.

The Russian began the tournament by upsetting Maria Sharapova in three sets and has not lost a set since. Kirilenko landed in her maiden Grand Slam quarterfinal when world No. 2 Dinara Safina retired due to a lingering back injury with Kirilenko ahead 5-4 in the first set.

Zheng, a speedy Chinese baseliner, owns big-match experience; she appeared in the Wimbledon semifinals in 2008. In Kirilenko, she encounters a fifth straight player outside the top 10.

Prediction: Zheng in three.

Ravi Ubha is a frequent contributor to ESPN.com.