Nishikori wins, says Li Na inspired him

Kei Nishikori shocked Jo-Wilfried Tsonga to become the first Japanese man to reach the Australian Open quarter-finals for 80 years Monday, but defeat for Zheng Jie ended China's hopes.

Nishikori roared back from a set down to stun the powerful 2008 finalist in five sets and set up a last-eight tie with Britain's Andy Murray, showing the form that has seen him rocket up the rankings.

Zheng, however, crashed out in straight sets at the hands of Italy's Sara Errani to end China's singles interest on Chinese new year's day -- and a day after last year's runner-up, Li Na, went out to Kim Clijsters.

Nishikori, the 24th seed, was forced to dig deep to oust sixth seed Tsonga, 2-6, 6-2, 6-1, 3-6, 6-3 in 3hr 30min in sweltering conditions on Hisense Arena.

He is the first Japanese man to reach the last eight at the Australian Open since 1932, when there were two in the quarters, and also became only the second Japanese man to reach a grand slam quarter-final in the open era.

"This is the first quarter-final for me. My (previous) best result is the 2008 US Open round of 16 and I played well at the end of last year and now it's like this. So, yeah, I feel I'm stepping up," Nishikori said.

"I'm happy to get to the top in Asia and hopefully I can be like Li Na for the men."

China's Li became Asia's first singles grand slam winner when she won last year's French Open.

A confident Nishikori, who also defeated France's Tsonga at last year's Shanghai Masters, said he was full of confidence but admitted fourth seed Murray posed a daunting challenge.

"We played at the end of last year. He kind of destroyed me. But I have no pressure now," Nishikori said, referring to Murray's 6-3, 6-0 win in Shanghai.

"I learned a lot of things from him. It's going to be tough, but I will try to play my best tennis," added the Japanese, who will break into the top 20 after the Open.

Nishikori, 22, broke Tsonga's serve six times and cashed in on 70 unforced errors, 40 of them on his big forehand. The Frenchman said Nishikori had proved a difficult opponent in the Melbourne heat.

"When you have a guy in front of you who returns everything, even when you serve at 215 (kilometres per hour, 134 miles an hour), it puts lot of pressure on you," he said.

"It's tough to play against him because he runs a lot and everything's coming back."

Meanwhile Zheng, who won her fourth WTA title in Auckland this month and had impressed in Melbourne, slipped to a comprehensive 6-2, 6-1 defeat to Errani.

The Chinese world number 38, who reached the semi-finals in Melbourne in 2010 but had wrist surgery at the end of the year, hit a whopping 47 unforced errors and was broken six times.