SYDNEY, Australia - Qualifier Yulia Putintseva ambushed No.4 seed Sloane Stephens at the Sydney International, coming from a set and a break down to seize their second-round scrap 3-6, 7-6(4), 6-0 in a two-hour, three-minute whirlwind of creative shotmaking.

It is Putintseva's sixth career Top 10 victory, second Top 5 win following her defeat of Dominika Cibulkova en route to the 2017 St Petersburg final and second consecutive win over Stephens following an equally dramatic 5-7, 6-4, 7-6(3) triumph in the first round of Nurnberg last year.

The American, who served for the match at 5-4 in the second set, will draw some comfort from the fact that the early Nurnberg loss to Putintseva was immediately followed by a run to her second Grand Slam final at Roland Garros, and will be hoping that history will repeat next week in Melbourne.

Initially, though, it was Putintseva who couldn't quite find the range needed to overcome a stellar Stephens. Tennis is often said to be a game of inches, and as one putative forehand winner after another from the Putintseva racquet drifted fractionally into the tramlines, the 24-year-old would have been more aware of that than ever. One lost her the opening game; two in a row put her down break point in the fourth. A razor-sharp Stephens, who would be unbeaten at net in the first set, seized the only break point chance in the first set with an exquisite volley.

Winning 80% of both her first and second service points, the 2017 US Open champion was at her impenetrable best off the baseline for a set and a half: patiently rallying with both width and depth to push Putintseva around the court, before injecting her trademark lightning flashes of pace to capture the point. A forehand down the line sealed the first set; an inside-out forehand opened the second en route to an immediate break of serve.

A brace of backhand winners down the line for Putintseva clawed that break back for 2-2, and in retrospect foreshadowed later events in the match, even if Stephens immediately regained her break advantage for 3-2. The Roland Garros and WTA Finals runner-up seemed to have mastery over every element of her game as she made her way to the brink of victory, blending power and touch and striking winners from both offensive and defensive positions.

Few scenarios get Putintseva's blood - and fists - pumping like the prospect of an unlikely comeback, though, and the two-time Roland Garros quarterfinalist scented opportunity as her opponent served for the match. Now, it was the former junior World No.3 who was confounding Stephens with sudden injections of pace - and as a forehand from the latter found the net to make the score 5-5, Putintseva was in her element, exhorting the Sydney crowd to get to their feet.

With her inspiration renewed, Putintseva began to peak as the set entered a tiebreak. The backhand down the line made three winning reappearances, including a stunner of a shot to bring up set point - taken immediately as a Stephens backhand sailed long.

And in the deciding set, the 5'4" Kazakh was simply irresistible as she struck an array of varied, creative winners that limited Stephens to just nine points in a half-hour stanza. In the first game, a cunning short slice set up a fizzing pass for Putintseva en route to breaking serve; in the third, she came up with a brilliant forehand pass at full stretch, followed it with a frankly disrespectful clean dropshot return winner, and followed that with a full-power return that left Stephens flailing.

Both players served well over the course of the match, with Stephens' overall first serve percentage ending up at 71% and Putintseva's at 75%. In the decider, the latter raised her first serve numbers to an untouchable 82% - and unable to find a way back in, Stephens began to hit out wildly as the end drew near, racking up 34 unforced errors as her frustration began to show.

Accelerating towards the finish line, the World No.44 sealed the bagel set on her first match point, slotting a backhand winner - her 25th of the day - crosscourt, having powered through the decider without facing so much as a game point. Up next in the quarterfinals is the challenge of No.7 seed Kiki Bertens, while Stephens - having lost two bagel sets in Sydney - heads to Melbourne in need of an injection not just of pace but form.