NEW YORK (Kyodo) -- Kei Nishikori and Naomi Osaka reached the second round of the U.S. Open with straight-sets wins in their respective men's and women's first-round singles matches on Tuesday.
World No. 19 Nishikori beat Germany's Maximilian Marterer, ranked 50th, 6-2, 6-2, 6-3 in their first match to set up a second-round clash with Gael Monfils of France on Friday at the USTA Billie Jean King National Tennis Center.
Nishikori, a finalist in 2014 and a semifinalist in 2016, said he played a "perfect game" against the 191-centimeter tall left-hander, winning four straight games in the opening set and playing aggressively from the baseline in the next two sets.
"It was a game with quality content and I was able to get off to a good start," Nishikori said.
"I played my forehand net shots well and hit good flat backhand returns. I hope to keep this up in the second round," he said.
Earlier in the day, Osaka breezed past Laura Siegemund of Germany 6-3, 6-2 in 1 hour, 18 minutes, winning her opening match at the U.S. Open for the third year in a row despite a low first-serve percentage of 51 percent.
"I wasn't able to play the way I wanted to, but I have to give myself credit for avoiding getting stuck in a pushing rally. I have to work on my serves," Osaka said.
Osaka will face Julia Glushko of Israel in her next match.
Elsewhere for Japan in the first round of the men's singles, Yuichi Sugita, Taro Daniel and Yoshihito Nishioka were all eliminated. Nishioka was defeated by five-time champion Roger Federer 6-2, 6-2, 6-4 in the night session on Arthur Ashe Stadium.