Winning 79 percent of points on his first serve and hammering down seven aces, Nishikori converted seven of his 15 break point opportunities and took 2 hours, 10 minutes to brush the former big hope of French tennis off Court Suzanne Lenglen at Roland Garros.
"I think it was solid match," Nishikori said. "I think it's not easy to play three straight sets easy. So you know, there are some ups and downs, and I think I fought through pretty well."
The 25-year-old Nishikori, a US Open finalist last year, is among the big outsiders at the French Open after defending his Barcelona title and making it to the semifinals in Madrid and the quarterfinals in Rome, where he lost to top-ranked Novak Djokovic.
Nishikori, who moved to the United States when he was 14 and has been coached by former French Open winner Michael Chang since last year, is the highest-ranked Japanese player ever. Japan started with five men in the French main draw -- the most since 1967, when there were six, and the most at any major since Wimbledon in 1973, when there were also five.
"It's great to see many Japanese players here, and I think men's tennis got much better right now in Japan," said Nishikori, who used to be nicknamed "Project 45" when his goal was to reach the No. 45 rank so as to be one spot higher than the best ranking achieved by any Japanese man.
"Those two young guys, Taro and Yeshi, are playing great tennis," Nishikori said. "They qualified for the US Open too. Now they qualified here, so it's great to see for Japanese tennis."
Last year at Roland Garros, Nishikori lost in the first round after fighting back problems.