Tennis: Chang-backed Nishikori eyes titanic Nadal upset

Kei Nishikori believes momentum and the influence of Michael Chang can carry him to the biggest upset of his career against the mighty Rafael Nadal at the Australian Open Monday.

The Japanese star ended America's representation in the men's singles with a straight-sets win over Donald Young to set up a date with the world number one Nadal in the last 16.

Asia's most accomplished men's player will have to overcome the daunting challenge of beating the 13-time Grand Slam champion if he is to repeat his best Slam result, when he reached the last eight in Melbourne in 2012.

Nishikori, seeded 16, has taken only one set in five losses to the Spanish superstar and will be the underdog. But he gives himself a chance after three solid wins at the tournament so far.

"He's obviously playing really well, especially here. We've played five times and I haven't beat him yet, so hopefully I can play good against him," Nishikori said.

"But I'm playing well. I'm really confident and my body is good. Everything is working well. If I can play best tennis, I think I have some chance to win."

Former French Open champion Chang is working in an advisory capacity with Nishikori, who is aiming to crack the world top 10 from his current 17 ranking.

"He's giving me a lot of good advice. He knows a lot of players. He gives me good tips for tactics," Nishikori said. "I think we've been working well. He's giving me confidence and it's going well."

Nishikori came through the searing heat of the opening week without expending too much energy, after being taken to five sets in his opening match with Australian Marinko Matosevic.

He won in straight sets against Dusan Lajovic and then dominated Young, winning 17 of the last 18 games as the American fell apart after a promising start.

"It was good to fight through the first round with Matosevic. After that I was playing much better and playing well, winning not easy, but in three sets," he said.

"My body is holding up well, so it's going to be interesting for my next match."

Nadal, who blasted his way into the round of 16 with an awesome win over Frenchman Gael Monfils on Saturday, knows Nishikori's strengths and is ready for him.

"Kei is a great player. He's able to play very aggressive, make the difficult things easy," he said. "He's very quick and will be a very tough opponent for me. He's playing great. It will be a tough one."