BEIJING, China - No.8 seed Kiki Bertens narrowly avoided a first-round upset at the China Open, overturning a break deficit in the final set to fight past Donna Vekic 3-6, 6-1, 7-6(3) in two hours and 20 minutes.

The Dutchwoman had compiled just a 4-6 win-loss record since reaching the Palermo final in July, but came up with 33 winners to 29 unforced errors while bringing her formidable serve to bear when it counted, tallying 10 aces in total, to notch up her first Top 30 win since defeating Aryna Sabalenka in the Eastbourne quarterfinals in June. This result also levels the head-to-head between Bertens and Vekic at three wins apiece, with Bertens edging ahead 2-1 in their 2019 series - having lost to the Croat from two match points up in the second round of Brisbane, but gaining revenge in the St Petersburg final.

Vekic has enjoyed a career-best season this year, and much of the quality that has taken her to the brink of the Top 20 was evident from the outset as the US Open quarterfinalist opened with a sequence of bold ballstriking. The 23-year-old's signature forehand was clicking smoothly, punishing any second serves or short balls that Bertens offered up - as well as smacking away a few of the Dutchwoman's heavily topspun attempts to push Vekic back. 

But so were all the other facets of Vekic's game: the World No.23 advanced confidently into the forecourt, where she was able to both blast drive volleys and show off her touch on a number of half-volley gets. A coolly executed dropshot paved the way to the first break of the match for 3-1 - one that would prove decisive. Clutch serving extricated Vekic from the danger of an immediate break back - and thereafter would see her over the line to take a one-set lead.

But if the serve had been one of Vekic's greatest assets in the opening stanza, with the two-time WTA titlist landing 70% of her first deliveries, it would become a crucial weakness in the second set as that number plummeted to just 40%. Taking advantage, Bertens swarmed the net with aplomb, breaking in the second game and never looking back. The St Petersburg and Madrid champion's defence was also beginning to have an effect: repeatedly, her ability to chase down Vekic's biggest strikes was eliciting errors from her opponent.

The latter stages of the set saw Vekic collapse somewhat, losing eight of the last nine points in a flurry of double faults, errors and inability to return the increasingly impregnable Bertens serve.

However, the two-time WTA titlist gathered herself for a charge in what would prove to be a knife-edge deciding set. Reining in her forehand and pressuring the Bertens serve, Vekic came through a series of tight games to break for 3-1, nailing a pass as Bertens' drive volley clipped the tape to sit up invitingly.

But Vekic's double fault tally was mounting; it would eventually reach nine, with a pair immediately beckoning Bertens back into the match. Thereafter, momentum shifted unpredictably between each player. A sequence of winners from both wings captured a second break, and third straight game for Bertens - but Vekic, finding her best tennis when behind, levelled at 4-4.

Once again, a pair of double faults proved Vekic's Achilles heel as Bertens regained the break - but the 2016 Roland Garros semifinalist was unable to serve out the win, with her own fifth double fault conceding the game.

Appropriately enough, then, a tiebreak had to decide the match - and, having been unable to hold on to a break lead twice in the final set, Bertens was belatedly able to dominate with her delivery in it. Of her first four service points, the 27-year-old posted a 10th ace, a simple one-two punch and two service winners. With Vekic increasingly breaking down first in the longer rallies on her own serve, eventually tallying 43 unforced errors to 25 winners, Bertens was able to seal an emphatic tiebreak on her second match point to set up a second-round clash against either 19-year-old Dayana Yastremska or 2017 champion Caroline Garcia.