BEIJING, China - No.4 seed Naomi Osaka extended her winning streak to five, kicking off her 2019 China Open campaign with a 6-3, 7-6(5) defeat of Jessica Pegula in one hour and 31 minutes.

In her first meeting with the American, Osaka dictated proceedings with her weight of shot throughout, maintaining a first serve winning percentage of 76% and striking 26 winners. The Australian Open champion also showed off her nimbleness around the court at key moments in the opening set, twisting around to flick a winning pass en route to a first break for 3-1 and chasing down a Pegula dropshot to pave the way to a 5-1 lead. A pair of bold backhands from the World No.76 would prevent Osaka from serving out the set at the first opportunity, but the Japanese No.1 made no mistake the second time, nailing a drive volley and three consecutive service winners for an emphatic love hold.

A tighter second set saw Osaka's level dip as the former World No.1's game began to leak mistakes: having committed only seven unforced errors in the first set, the Toray Pan Pacific champion totalled 19 in the second. Now, it was Pegula making more consistent inroads into the Osaka serve, forcing break points in consecutive games - but the 21-year-old was clutch when she needed to be, blitzing a backhand winner down the line to save the first and a unreturnable serve to fend off the second.

Indeed, protecting her serve well while pressuring Osaka with the depth of her returns, Pegula would come within two points of forcing a decider at 5-4, 30-30. Again, though, the former World No.1 called on her power to escape danger, and immediately pounced to capture the Pegula serve for the first time in the set as the Washington champion lost control of her own groundstrokes.

Attempting to close out the match, though, Osaka still struggled to shake off a valiant Pegula. The two-time major winner was unable to serve out the win, and let a 4-1 lead in the ensuing tiebreak slip to fall behind 4-5. But despite these moments of carelessness, Osaka was able to summon her best tennis with her back to the wall, avoiding having to face set point with an eighth ace.

In the tightest moment of the match, it was Pegula's tactics that let her down. The 25-year-old had found success by going all out on return, but two attempts to inject pace resulted in consecutive errors to seal victory for Osaka, who will face either Jil Teichmann or qualifier Andrea Petkovic in the second round.