Osaka became the first winner on a stacked Thursday slate in an hour and 43 minutes, coming from an early break down in the first set after losing serve for the only time in the match at 1-1.
The World No.1 was forced to battle hard to keep her lead, however, as she saved break points at 2-2 and 3-3 before finally converting her third chance on the Slovak’s serve in the eighth game to break for the second time.
From there, Osaka kept the former World No.4 at arms’ length, breaking serve to start the second set and staying ahead for the duration.
She saved all four break points she faced in the second set, including three in a key eighth game which would’ve seen Cibulkova pull even and get back on serve.
The Slovak, a former quarterfinalist in Rome seven years ago, did not play poorly in the match overall, finishing with a positive winner-to-unforced error ratio to 17-14.
Nonetheless, she managed to win just one of the eight break points she created in the match, and allowed Osaka a whopping 15 break point chances on her serve overall.
Osaka bosats a winning head-to-head against either of her round of 16 opponents, beating Buzarnescu in their only career meeting on grass last June, and owning a 2-1 edge against Goerges.