The former world number one didn’t make an unforced error in the first set in what ended up being a nostalgic outing at Flushing Meadows.
Having won twice in New York, Osaka’s extended break from tennis over the past few years has offered up scant opportunity to truly analyse her title prospects this year.
Next opponent Muchova has also seen a lengthy stint away from the match court, with a wrist injury sustained last year only seeing her return to the tour in June.
With convincing wins for both players in their openers, the jury is still out on who might come through this one.
The blistering shot-making followed by a sheepish grin after the match has always marked Osaka out as a fan favorite on tour.