TIANJIN, China - No.1 seed Karolina Pliskova got her last-minute Tianjin Open campaign off to a hard-fought start over an opponent who refused to be dismissed easily, eventually coming through 6-2, 6-7(3), 6-3 in two hours and 30 minutes exactly over the unseeded Varvara Lepchenko.

The Czech had taken a wildcard into the tournament in a bid to help clinch her place at the BNP Paribas WTA Finals Singapore presented by SC Global: heading into the final two weeks of the Porsche Race to Singapore, five players remain in contention for the last three spots, and every win counts.

Pliskova will thus be content to score her fourth win in as many meetings over the American - and third in which she has come through a decider. Indeed, the eventual scoreline today would almost exactly replicate the pair's only previous Asian encounter - a 6-3, 6-7(5), 6-2 triumph for Pliskova in the 2014 Seoul final.

The scoreline of the opening set belied a tightly contested start to the match, in which five of the first six games featured at least one break point. Lepchenko, striking her forehand aggressively and moving Pliskova around the court, repeatedly dragged her higher-ranked opponent into knife-edge multi-deuce tussles. Although the World No.161 came out on the wrong end of one to drop serve in the fourth game, she immediately responded with a pair of brilliant forehand winners down the line to break the Tokyo champion right back.

Pliskova was not at her sharpest today, with the former World No.1, frequently conceding leads within games with cheap errors rather than pressing home her advantage, but a 74% first serve percentage proved efficient enough in the opening stanza. As the Stuttgart and Tokyo champion broke again for 4-2, Lepchenko's groundstrokes would crumble, with a series of shanked forehands leading to the final two games falling away rather suddenly for the 32-year-old.

By contrast to the opening act, the second set would settle into a pattern of comfortable holds through the first 11 games, punctuated only by a dead net cord giving Lepchenko a handful of break chances at 3-3. On the first, the former World No.19 sent a forehand down the line just long; Pliskova's famed serve would bail the 2016 runner-up out on two more.

Serving to stay in the match for a second time at 5-6, Lepchenko lapsed into error to offer up a match point to her opponent, but more strong hitting on the forehand side would save that - and then a rocket down the line off the same wing would seal the hold to force a tiebreak.

By now, it was the Québec City quarterfinalist - who had won just six WTA main draw matches in 2018 coming into this week - who was hitting with more authority; Pliskova, playing with decreased intensity and accuracy, would fail to get a toehold in the tiebreak, which Lepchenko took comfortably 7-3.

The World No.6 had been able to take a lead on an autopilot level, but Lepchenko had battled hard to successfully transform the match into a dogfight - and as the deciding set got under way, there was little separating the pair. But it was Pliskova who was able to raise her game: an errant Lepchenko backhand conceded the break in the fifth game, and the 26-year-old extended her lead by some judicious deployment of dropshots and some remarkable flicked angles at full stretch.

Getting over the line still wouldn't be smooth sailing, even after the Australian Open and US Open quarterfinalist toughed out three deuces to capture a double break lead. Lepchenko saved a further two match points - the second with a clever backhand slice fake-out that left Pliskova flat-footed - to break for 3-5, with the 2014 Seoul runner-up visibly relishing the fight whenever her back was against the wall.

Serving to stay in the match for a third time in total, Lepchenko fired another pair of forehand winners, one plum on the line, to stave off a fourth and fifth match points. But an epic comeback wasn't to be: a fourth double fault followed by a net cord bouncing her forehand wide put the left-hander down match point for the sixth time, and this time Pliskova made no mistake with a forehand down the line that forced the error.

Elsewhere, the biggest upset of the day came courtesy of Russian qualifier Veronika Kudermetova as the World No.122 ousted 2014 champion Alison Riske 5-7, 6-1, 7-5; but No.5 seed Hsieh Su-Wei survived her third meeting with Ajla Tomljanovic in the past month, defeating the Australian 7-6(4), 7-5 to take the overall lead in their head-to-head.