Surprise packets Kei Nishikori and Marin Cilic are set to contest one of the most unlikely grand slam finals in history at the US Open in New York.

Japan’s Kei Nishikori, the first Asian man to make a grand slam final, faces fellow first-timer Marin Cilic for the US Open title on Monday (7am Tuesday AEST) hoping to open a new frontier in tennis.

After Nishikori and Cilic disposed of top seeds Novak Djokovic and Roger Federer in the semi-finals, the championship match will be the first not to feature either Djokovic, Federer or Rafael Nadal since the 2005 Australian Open.

No wonder Nishikori is still pinching himself after knocking out Wimbledon champion and seven-time grand slam winner Djokovic.

“I am a little bit surprised for me to play the final,” said the 24-year-old, whose previous best grand slam run had been a quarter-final at the 2012 Australian Open.

His win over Djokovic, his second in three career meetings with the Serb, followed a five-set quarter-final triumph over fifth seed Milos Raonic and another five-set, four and-a-quarter-hour marathon against third-seeded Australian Open champion Stan Wawrinka.

His success comes despite his having to sit out the Toronto and Cincinnati Masters on the eve of the US Open to have a cyst removed from his toe, a painful problem which almost forced him to skip New York.

“I just started playing points a few days ago before the tournament. I didn’t even know if I should come to New York, so I wasn’t expecting anything actually,” said the 10th seed.

His coach Michael Chang, a grand slam champion at the 1989 French Open, believes a Nishikori triumph could have the same impact as Li Na’s breakthrough major at Roland Garros in 2011.

“Obviously with Li Na having as much success as she’s had the past few years and Kei’s done very well,” said Chang.

“This year’s really been a breakthrough year for him and I wouldn’t be surprised if that really propels a lot of Asian tennis, particularly on the men’s side because women have really been doing well.

“It’s going to give them a lot of confidence to go out and play. A great example is what Venus and Serena have done for young American women.”

If form is any guide, then Nishikori should race away with the title as he boasts a 5-2 record over the 25-year-old Croat, including both meetings this year, on hard court in Brisbane and on Barcelona clay.

However, they have split their two past US Open duels, with Nishikori winning in 2010 and Cilic coming out on top two years ago.

Cilic has endured a tough journey over the last year, albeit a more controversial one.

The 25-year-old 14th seed missed the 2013 US Open to serve a doping ban handed out after he tested positive for a banned stimulant contained in an over-the-counter supplement.

Fired up by indignation over the way the case was handled, Cilic is a man on a mission having bettered his previous grand slam best of a semi-final spot at the 2010 Australian Open.

Playing in his 28th grand slam event, Cilic, however, wondered if his time in the biggest spotlight would ever come.

“When you are young on the tour you always feel you have enough time,” said Cilic, who routed Federer in straight sets.

“You have a lot of grand slams. You’re going to do well. But when the time starts to pass by, you are more anxious if it’s going to happen or it’s not going to happen.”