HONG KONG (AFP) - Australia's Lleyton Hewitt on Tuesday said Kei Nishikori was developing into a serious contender at tennis Grand Slams as he bids to emulate China's Li Na by becoming an Asian major winner.

Hewitt, 32, who will share the stage with China's Li at next month's BNP Paribas Showdown in Hong Kong, said Japan's world No.16 stood the strongest chance of becoming the first Asian-born male singles Slam champion.

The former world No.1 fought past 24-year-old Nishikori in three sets on the way to winning last month's Brisbane International, and he said the Japanese star has "really stepped it up".

Sixteenth-ranked Nishikori, now advised by former French Open-winner Michael Chang, also pushed top seed Rafael Nadal in January's Australian Open round of 16 in one of his best Grand Slam performances.

"In terms of the Asian guys, obviously it's led by Nishikori at the moment and he has a very good chance in the future of being a contender at the Grand Slams," Hewitt told a teleconference ahead of the March 3 Showdown.

"I think he's really stepped it up in the last year or so, over five sets in the majors. So he's probably the best chance (of a Slam win), I would say, at the moment. He plays really well on all surfaces as well."

Hewitt will play Czech world No.7 Tomas Berdych at the Hong Kong exhibition event, while Li, fresh from winning her second Grand Slam title at the Australian Open, will play former US Open-winner Sam Stosur.

He was full of praise for the "fantastic" Li, and said the 2011 and 2013 runner-up fully deserved her win in a tournament dubbed "The Grand Slam of Asia-Pacific".

"It will be massive," Hewitt said of the exhibition event at the new Hong Kong Velodrome. "She's such a big name in Asia now and in Asian sport in general.

"It's been fantastic, what she's done. She deserved to win the Australian Open, she's been runner-up a couple of times there in the past.

"It's good for the tournament, especially back in Australia, knowing how hard they've worked to turn that into the Australasian Grand Slam as well.

"That was an important time that Li Na won this year, I think it was important for the tournament but also for the tennis in that region."

The world No.3's win came at the start of a year in which her home city, Wuhan, will host a major new tournament and Singapore will hold the end-of-season WTA Championships in October.