Melbourne: Rafael Nadal battled through a five-set firestorm to book histicket in the Australian Open quarter-finals as Martina Hingis and KimClijsters set up an enticing clash.

Top seed Maria Sharapova also marched on, outmuscling fellow Russian VeraZvonareva 7-5, 6-4 to set up a match with another compatriot, 12th seed AnnaChakvetadze, who undid eighth seed Patty Schnyder 6-4, 6-1.

But fifth seed James Blake, who won in Sydneythis month, suffered his first loss of the season and crashed in straight setsto Chilean tenth seed Fernando Gonzalez, who now meets the second seeded Nadalfor a spot in the semis .

Germany's12th seed Tommy Haas tamed eighth seeded Argentine David Nalbandian in foursets and will face third-seeded Russian Nikolay Davydenko in the quarters.

Spain's Nadal was pushed to the limit by 15th seed Andy Murray, trading thefirst four engrossing sets before the Briton crumbled in the decider, goingdown 6-7 (3/7), 6-4, 4-6, 6-3, 6-1 in close to four hours.

"It was a very tough match. He's a great player," said Nadal.

"It was a very important match for me. I needed to win a tough matchlike that against a top player. I tried to fight for every point," hesaid.

Hingis, seeded six, needed all her big-match experience to overhaul 19thseed Li Na 4-6, 6-3, 6-0, coming back to dismantle the Chinese woman's game andsecure a quarter-final appearance here for a ninth time.

In an intriging match-up, she will play Clijsters, who beat her at the samestage last year, ending the Swiss star's Grand Slam comeback after a three-yearinjury hiatus.

"I know I have to come out one hundred percent and be ready from thebeginning, otherwise I'll be run over," she said of Clijsters, the fourthseed.

"That's the key. I have a day rest, and practice, sleep well, givemyself the best shot,"  she said.

Clijsters has been in scintillating form and was clinical against Slovakpin-up Daniela Hantuchova, powering through 6-1, 7-5, and is looking forward topitting her wits against one of her best friends on tour.

"It always a pleasure to play against her, she's such a greatchampion," she said.

"We get along really well on and off the court. When we get on thecourt we try to play our best tennis but once we get off the court and backinto the locker room we have a joke about everything and that's the way itshould be," she said.

"We're professionals and it's great to see her doing well again," shesaid.

Top seed Sharapova displayed lapses of concentration against Zvonareva andacknowledged she needed to improve against Chakvetadze, who won the lead-upHobart International tournament.

"I thought I played a lot better today than I did in my previous roundsbut I'll definitely have to step it up against her," said Sharapova, whosevictory handed her the number one world ranking.

She earned the right after defending champion Amelie Mauresmo tumbled out inthe third round and former number one Justine Henin-Hardenne missed thetournament for personal reasons.

With defending champion Roger Federer safely into the quarter-finals, Haas,Gonzalez, Davydenko and Nadal joined him Monday.

Gonzalez upset Blake 7-5, 6-4, 7-6 (7/4) while Haas wore down Nalbandian, asemi-finalist last year, 4-6, 6-3, 6-2, 6-3.

Davydenko, who has been anonymous working his way to the last eight,qualified for his third straight Australian Open quarter-final with a 5-7, 6-4,6-1, 7-6 (7/5) win over Czech 13th seed Tomas Berdych.