Japan's Nishikori has grand slam plans TOKYO (Reuters) - Japan's Kei Nishikori has mapped out a three-year plan to challenge for grand slam glory after blazing his way to a second career title. The 22-year-old told Reuters that overcoming suffocating pressure to win the Japan Open had given him the belief he can break into the top 10 and walk with the game's giants. "I think winning a grand slam is possible," the swashbuckling Nishikori said in an interview after beating Milos Raonic 7-6 3-6 6-0 in Sunday's Tokyo final. This week I probably played the best tennis of my life. Breaking into the top 10 is the goal now. To win a (ATP) 500 title in Japan has special meaning. Until now I had never been able to play well in Japan. "There was so much pressure," added Nishikori, set to rise from 17th to 15th in the world rankings after becoming the host country's first Japan Open champion. I thought I lacked mental toughness. Being able to break through that barrier playing my best tennis was amazing. I still can't believe it. Nishikori's storming run through a quality field headed by last year's winner and U.S. Open champion Andy Murray showed the Japanese he had the game to compete at the highest level. "Winning a tour title was this year's objective," said Nishikori, who burst onto the scene as an 18-year-old by winning in Delray Beach as a 244th-ranked qualifier in 2008. From now I'll be aiming to win a Masters event. I reached a semi-final last year (in Shanghai). I want to beat the top four players in the world. That's still a big wall for me but that's my goal. Nishikori showed flashes of genius in Tokyo, demonstrating the potential to become a serious contender at future grand slam tournaments, and often leaving opponents gaping in dismay. "Winning the Japan Open has made me feel I've got a little closer to them," he said of Roger Federer, Novak Djokovic, Rafa Nadal and Murray. Obviously they're fantastic players to me. But playing tennis like I have been this week consistently is the aim now. I'm still a little bit off winning a grand slam. In the next two or three years I have to strengthen my body to be able to withstand seven five-set matches. First make my body stronger, play well more consistently and once I've combined the two things then I'll have a chance to win a slam. Nishikori, who floored world number six Tomas Berdych on his way to the Tokyo final, had feared his career could be over when an elbow injury cut short his 2009 season. "That was the toughest time for me," said Nishikori, who reached the quarter-finals of this year's Australian Open. I didn't know if I would play again after the elbow surgery. Nishikori, whose maiden title was the first by a Japanese man since Shuzo Matsuoka beat Todd Woodbridge in Seoul in April 1992, finished last year ranked 25th. His run-and-gun style worked to perfection at the Japan Open, and forced players ranked above him to take notice. "Kei is a superstar," said Raonic after the Canadian had suffered the dreaded 'bagel' in the third set of the final. He has the potential to do great things. Nishikori, already a huge celebrity in Japan, blushed when asked how good he could be become. "The other players will look at me differently now," Nishikori said with a toothy grin. This tournament will take my ranking up so I want to keep improving.