TOKYO, Japan - Unseeded Donna Vekic backed up her first-round upset of No.5 seed Sloane Stephens in style, coming from a double break down in the second set to defeat Johanna Konta 6-3, 7-5 in one hour and 32 minutes.
The result moves the 22-year-old into her fifth quarterfinal of the year - and first ever at Premier level. It also slightly redresses a head-to-head that Konta had led 3-1 before today. Vekic's only previous victory over the Briton had been a 2-6, 7-6(3), 7-5 win in the 2017 Nottingham final to seal her second and most recent title.
Aside from one delicious reflex volley in the first game, Konta began the match poorly. Despite finding herself with the upper hand in the majority of rallies - partly due to Vekic's inability to find her first serve - the World No.43 was unable to finish them off, committing 10 unforced errors from commanding positions in the first five games alone, mostly off the forehand - one of which put her down a break in the third game. (Ultimately, Konta would tally 38, with a level 19 in each set.)
The Croat, meanwhile, kept her opponent honest with heavy, solid hitting of her own, totalling 19 winners to 16 errors over the course of the match. Despite landing a mere five first serves over the course of the first set for a percentage of 21%, she would not face a break point during it - a testament to both the quality of Vekic's second serve, behind which she won 68% of the points, and her clutch play on big points.
Vekic would also prove the more versatile player, with a number of crafty dropshots and pinpoint lobs catching Konta out as well as her more standard power.
But the start of the second set marked a turnaround of sorts: striking immediately on the Vekic serve, Konta struck a huge forehand return winner on the second point, and was rewarded by a rattled opponent leaking a series of groundstroke errors to fall behind a break.
Suddenly, the former World No.4 had found to her range, particularly on the forehand that had let her down so much in the previous set. Konta reeled off winners both crosscourt and down the line from that wing as she leapt to a 4-1 lead, the double break sealed with Vekic's fifth double fault as the Washington finalist continued to struggle with her serve.
But with momentum on her side, it was Konta's backhand that would open the window slightly for Vekic, going awry three times - with an excellent Vekic dropshot in between - to concede one of the breaks. The World No.45 seized her opportunity with gusto to notch up her most emphatic service game of the match - two unreturned serves, one ace and one forehand winner - that marked an increase, at last, in her first serve percentage to 54% in the second set.
"From then I had to serve better," recalled Vekic afterwards. "And then it was easier to win games on my serve. I found some rhythm on my serve towards the end of the match and hopefully I can keep it going tomorrow."
Reducing the deficit paid off. Serving for the set, Konta descended once more into wildness, with three extremely errant forehands and a smash several metres long levelling the score at 5-5. Though Vekic's next service game was a struggle, with the two-time WTA titlist committing her sixth and seventh double faults and crawling through four deuces, she once more found an unreturnable serve when it mattered most to hold. Now serving to stay in the set, Konta picked up where she had left off with a smash that bounced on her own side of the court and two wide groundstrokes for another love break.
Having reeled off six of the final seven games, Vekic will seek to keep her milestone run going as she faces No.2 seed Caroline Garcia in the quarterfinals. The Tokyo debutante has been enjoying her first time in the Japanese capital - "It's my first time here, and I'm really enjoying it so far," she told reporters afterwards. In particular, she had spent her day off yesterday visiting the renowned shopping district of Ginza.