Osaka powers into last-eight of Wimbledon warm-up
The four-time Grand Slam winner dispatched home favourite Suzan Lamens 6-2, 6-2 in less than an hour, her powerful service and groundstrokes proving too much for the Dutchwoman.
The Japanese woman, now ranked 125th in the world, will face Canada's Bianca Andreescu, who came through her match against sixth-seed Yuan Yue from China in straight sets.
"I definitely do feel more relaxed. I feel more calm with the plan I have and just really grateful to be back," said Osaka.
She added that the key to her good form was to be "more comfortable returning and accepting mistakes as they come."
The first set went on serve until the sixth game, both players struggling to adapt to blustery conditions.
Then Osaka took the initiative, breaking the Dutchwoman's service with a series of powerful drives off both wings, helped by some unforced errors from Lamens.
More errors in Lamens' next service game handed Osaka the first set 6-2 in just 26 minutes of play.
The Japanese was too strong for her opponent at the start of the second set as well, breaking her first service game with a string of winners to race into a 3-0 lead. She wrapped the match up as Lamens dumped another groundstroke into the net.
By Osaka's own admission, grass is not her favourite surface, her four Grand Slams coming on hard courts in the US and Australian Opens.
She has never made it past the third round on the Wimbledon grass but appears to be gradually coming back into the form that took her to world number one.
Osaka had a match point against eventual French Open winner Iga Swiatek in the second round, the sternest test the world number one faced on the Paris clay.
