Four-time Grand Slam winner Naomi Osaka fired 16 aces past Serbian qualifier Olga Danilovic to earn a 7-6(6) 7-6(4) victory at the Bad Homburg Open in Germany on Monday for her first win on grass this season less than a week before the start of Wimbledon.

The 27-year-old Japanese player, who had lost in the first round at her last two tournaments — the French Open and the Berlin Open — had won her first title in May in almost two years following a maternity break.

Osaka, who had reached the third round of the Australian Open in January before retiring injured, has not had back-to-back wins on any surface since the Italian Open in May. She is currently ranked 56th in the world.