Two-time winner Kei Nishikori got past Borna Coric in the first round of the Japan Open in Tokyo on Monday.
The Japanese second seed dropped the first set to the Croatian before comfortably reaching the next round 2-6, 6-1, 6-2, in two hours and nine minutes.
Nishikori will now face American Sam Querrey in the next round.
Querrey played well to beat Alexandr Dolgopolov of Ukraine in straight sets, winning 7-6(5), 6-4.
In an all-Japanese clash, Tatsuma Ito won a three-setter against Yoshihito Nishioka 3-6, 6-0, 7-5, in two hours and 23 minutes.
In the final match of the day, Czech Republic's Jiri Vesely comfortably beat Japan's Yasutaka Uchiyama 6-4, 6-4.