Rafael Nadal set up a blockbuster Australian Open quarter-final with Andy Murray yesterday and Justine Henin's comeback stayed on track, but there was misery for Dinara Safina who pulled out injured.
On a day of upsets, the tournament ended for US Open champion Juan Martin del Potro and French Open champion Svetlana Kuznetsova. Second seed Safina limped out with a back problem during her fourth round clash with unseeded countrywoman Maria Kirilenko.
The 23-year-old Russian, the runner-up last year, battled the injury in late 2009 and withdrew from the Brisbane International this month.
She was trailing 4-5 and 30-40 when she walked towards the umpire and indicated her night was over.
"My back again. It suddenly hit me, it was getting worse and worse," said Safina, clearly in pain.
"I have no idea really how it could happen. It's really, really terrible."
Zheng Jie, meanwhile, rewrote the history books by becoming the first Chinese player to reach the last eight in Melbourne and will now play Kirilenko.
Spain's second seeded Nadal was put to the test by big-serving Croat Ivo Karlovic, who slammed down 28 aces, before he muted the challenge 6-4, 4-6, 6-4, 6-4.
It ensured an enticing last eight showdown with in-form fifth seed Murray after the Scot tamed another big-server, American John Isner, 7-6 (7/4), 6-3, 6-2.
"Murray is one of the more dangerous players on the tour, he can play aggressively and defensively," said Nadal, who has not won a tournament in eight months after being hampered by injury.
"I will have to play as well as I can and use my forehand."
Andy Roddick staged one of his great recoveries to come from behind and claim a five-set victory over Chile's Fernando Gonzalez and reach the Australian Open quarter-finals.
The American seventh seed looked in trouble when he fell behind two sets to one but clawed back for a 6-3, 3-6, 4-6, 7-5, 6-2 win over the 11th seeded Gonzalez, a former finalist here.
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