MOSCOW, Russia - Kristina Mladenovic picked up her fourth Top 10 win - and dealt a blow to No.2 seed Kiki Bertens' WTA Finals hopes in the process, capturing their Kremlin Cup quarterfinal 6-4, 2-6 6-1 in two hours and seven minutes.

The Frenchwoman - who also defeated Naomi Osaka in Dubai, Ashleigh Barty in Rome and Elina Svitolina in Zhengzhou - is once again finding form indoors in Russia: her sole career title to date came at St Petersburg in 2017,  at the same tournament one year later Mladenovic snapped a 15-match losing streak to reach the final again, and this week a career-best showing in Moscow has put her into her second semifinal of 2019.

For Bertens, though, the loss means that she has failed to overtake eighth-placed Serena Williams in her quest to seal a spot at the Shiseido WTA Finals Shenzhen - and will now require at least one withdrawal to compete in the year-end extravaganza, where she made the semifinals in 2018, with No.3 seed Belinda Bencic still able to overtake both Williams and Bertens with a final in the Russian capital.

In a tight opening set that saw both players perform better at net than off the ground, Mladenovic found herself under pressure first - but saved a break point in the fourth game with a bold serve-and-volley play before knocking off a neat backhand volley to hold. The 26-year-old then pounced in the next game, taking advantage of a flurry of errors from Bertens to capture the break with a fizzing forehand down the line.

That break would prove decisive as Mladenovic's constant changes of pace and direction continued to bother Bertens - although not before a knife-edge final game as the World No.45 attempted to serve the set out. She was forced to save three break points as her form began to oscillate - but it was Bertens who would miss two crucial passing shots before a backhand from the Dutchwoman, her 17th unforced error of the set, sailed over the baseline on Mladenovic's second set point.

Battling hard to keep her Shenzhen hopes alive, Bertens cleaned up her game to essay an impressive second-set volte face. Using her heavy forehand to take control of rallies earlier while reducing her unforced error count to seven,  the St Petersburg and Madrid champion broke twice to quickly leap out to a 4-0 lead.

By contrast, Mladenovic's switch-ups were beginning to seem less clear-headed: poorly executed dropshots sat up for Bertens to smack away, while her slices repeatedly found the net. A flurry of highlight reel points saw the two-time major quarterfinalist get on the board, seizing one of the breaks back with a brilliant lob at full stretch after chasing a Bertens counterdrop - but it was too late to save the set, as the World No.8 responded by pounding away eight of the next nine points to level the match.

However, Mladenovic's rediscovery of her touch would serve her well as the match entered its final set. Swarming the net, where she would win 11 out of 13 points in the final act, with intent and panache, the former World No.10 out-manoeuvred Bertens to gain an immediate break - and then backed it up by coming through a three-deuce tussle for another.

By now, a confident Mladenovic was firing on all cylinders. Throughout the match, Bertens had found a good deal of success by attacking her opponent's backhand side - but Mladenovic was finally able to withstand the strategy in that long third game, getting to break point via superb defence from that wing before surprising Bertens by driving a winner past the flat-footed 27-year-old. 

Consecutive backhand passes would seal the triple break and an unassailable 5-0 lead for Mladenovic. Bertens - who has made a habit of battling through arduous three-setters in recent weeks to keep her Shenzhen quest alive, having come through such matches against Donna Vekic and Elina Svitolina in Beijing, Alison Van Uytvanck in Linz and Kaia Kanepi in the second round this week - was increasingly faltering, racking up 11 more unforced errors as the decider got away from her. Though she would avoid the bagel set as Mladenovic failed to serve the match out, this would be a minor bump in the road for the 2017 St Petersburg champion, who simply turned around to break Bertens once more for the win.

In the semifinals, Mladenovic will face either No.3 seed Belinda Bencic - with the opportunity to end a second consecutive opponent's Shenzhen hopes if that is the case - or qualifier Kirsten Flipkens.