SEOUL, South Korea - Qualifier Timea Babos continued her recent revival at the KEB Hana Bank Korea Open with a 6-3, 6-3 upset of former champion Jelena Ostapenko in one hour and 19 minutes.

The Hungarian sank out of the Top 100 this February for the first time in five years, but a positive North American hard-court swing that included a semifinal at the Vancouver ITF W100 event and a second-round showing as a qualifier at the US Open spearheaded a return to her usual habitat last week. Having once again navigated through the preliminary rounds here, Babos demonstrated greater consistency and security behind her serve to hold off World No.74 Ostapenko, who sinks to a 15-23 record in WTA main draws this year.

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In many ways, the match encapsulated Ostapenko's season, with the Latvian showing intermittent flashes of brilliance but unable to string them together to gain any sort of momentum in the match - and the pendulum swinging towards mistakes when the stakes were raised. As is par for the course with the free-swinging 2017 victor, Ostapenko dominated the winner count with 26 to Babos's 19 - and indeed finished with a positive ratio, having committed only 25 unforced errors.

Frequently, too, the 22-year-old's shotmaking would draw gasps with its crowd-pleasing boldness - but Ostapenko's radar would go too far awry on big points for this to translate on the scoreboard. By contrast, Babos was both clutch and clean, keeping her own power in check with a mere seven unforced errors while going unbroken over the contest thanks in part to nine aces.

The final game of the first set was a case in point. Having grabbed the crucial break in the second game, Babos had conceded only one point behind her delivery to this point - but, serving for it, found herself 0-40 down thanks to a sudden flurry of errors. Yet Ostapenko was unable to take advantage of four break points, and the World No.92 would ultimately seal the set with a dropshot.

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In the second set, the double faults that have plagued Ostapenko in 2019 would rear their heads at inopportune times: a seventh conceded a first break in the fifth game. Serving to stay in the match, a wildly oscillating game saw the former Roland Garros champion deliver blazing winners and two more double faults to take her total to nine, while Babos struck out with aggressive returns of her own. As they had all match, the biggest points fell in Babos's favor: the 26-year-old fired a stunning backhand pass followed by a clean backhand return winner to take victory on her third match point.

In the second round, Babos will bid for her first WTA quarterfinal since reaching the Monterrey final in April 2018 against No.3 seed Karolina Muchova, who overcame Alison Van Uytvanck 6-4, 3-6, 6-2. Elsewhere, fellow qualifier Ana Bogdan also sprung an upset, defeating No.6 seed Polona Hercog 6-3, 3-6, 6-1; but 18-year-old phenomenon Anastasia Potapova came from a break down in the first set to move past wildcard Han Na-Lae 7-6(4), 6-1, while qualifier Priscilla Hon - who reached her only previous WTA quarterfinal here in Seoul two years ago - ended Hiroshima semifinalist Mihaela Buzarnescu's mini-revival 6-3, 6-4.

Tuesday's play was concluded under the floodlights as the day's final match turned into an epic. Romanian qualifier Patricia Maria Tig, whose comeback from maternity leave has been one of the most impressive stories of 2019 and which has already netted her a Bucharest runner-up place and the Karlsruhe 125K trophy, found herself facing No.117-ranked lucky loser Danka Kovinic instead of No.1 seed Maria Sakkari following the Greek's withdrawal due to a right wrist injury. It took the World No.124 three hours and one minute to find a way past the dogged Montenegrin, but Tig eventually came through 6-4, 3-6, 7-6(3) in the 17th-longest WTA main draw match of the year to date.