Thursday is quarter-finals day at the WTA Dubai Duty Free Tennis Championships as the remaining eight players battle to advance to the final four. With all matches taking place on Centre Court, the schedule begins with 2013 champion Petra Kvitova of the Czech Republic taking on Latvia's former French Open winner Jelena Ostapenko. That is followed by a clash between two giant killers from the second round as Swiss qualifier Jil Teichmann, fresh from eliminating 10th seed Elina Svitolina, faces Russia's Veronika Kudermetova, who defeated defending champion Garbine Muguruza on Wednesday. The evening session begins with the blockbuster match of the round when two-time champion Simona Halep and Tunisian eighth seed Ons Jabeur go head-to-head. The last time these two met in Dubai, in 2020, <a href="https://www.thenationalnews.com/sport/tennis/dubai-tennis-simona-halep-digs-deep-to-overpower-ons-jabeur-1.981739" target="_blank">Halep edged an epic clash</a> in the second round on her way to winning the title. The day concludes with a match between two qualifiers as former French Open finalist Marketa Vondrousova plays Ukraine's Dayana Yastremska. Simona Halep is through to her third Dubai semi-final after producing an impressive performance to eliminate Tunisian eighth seed Ons Jabeur 6-4, 6-3. Halep, making her way back from a year disrupted by injury, was in fine form and will now be favourite to win her third title in Dubai. The former world No 1 led for the entire first set, even as breaks were exchanged, and broke for a third time to take the lead. Jabeur wrestled momentum away from the Romanian at the start of the second set to lead 2-0 but Halep swiftly turned the match back in her favour after winning four straight games. Halep maintained her advantage and closed out the victory on her second match point. The two-time Grand Slam champion will face Latvia's Jelena Ostapenko in the semi-finals. Russia's Veronika Kudermetova continued her fine form in Dubai after beating qualifier Jil Teichmann 6-2, 5-7, 6-4 to reach the semi-finals. Kudermetova, the world No 31, looked to be cruising when she broke twice to race through the first set and broke again to lead 2-1 in the second. However, Teichmann dug deep to turn the set around, winning three games in a row, and claimed the all-important break in the 12th game to level the match. Kudermetova resumed control at the start of the deciding set with an immediate break, before Teichmann once again fought back to level at 2-2. The Swiss then faltered on serve to hand Kudermetova a 5-4 lead and the Russian closed out the win on her second match point. Kudermetova will face the winner of the day's last match between Marketa Vondrousova and Dayana Yastremska. Jelena Ostapenko booked her place in the Dubai Duty Free Tennis Championships semi-finals after coming through an epic clash against Petra Kvitova 7-5, 5-7, 7-6. Ostapenko twice fought back as Kvitova served for the match in the second and third sets and saved a match point in a marathon tiebreak before claiming a closely-fought victory after two hours and 39 minutes. The Latvian world No 21 enjoyed a fast start to lead 4-1 but Kvitova took charge of the first set, winning four games in a row, and the Czech had the chance to serve out the set at 5-4. Ostapenko halted Kvitova's momentum to break back and level at 5-5 but it proved brief respite as the 2013 champion won the next two games to take the lead. Kvitova increased her advantage by earning a break in the first game of the second set, but Ostapenko fought back right at the death, breaking the Czech when she was serving at 5-4 and winning three games in succession to take the match to a decider. Both players exchanged early breaks in the third and most of the set stayed on serve, until Kvitova earned another break and another chance to serve for the match. Once again, Ostapenko came roaring back to level at 5-5 and after two services holds, a tiebreak settled this marathon clash. Just like the match that preceded it, the tiebreak was a closely-contested, back-and-forth battle. Kvitova established a 4-2 lead, before Ostapenko came back at 5-5 and it was the Latvian who had the first two match points, at 6-5 and 7-6. Ostapenko finally closed out the victory 11-9 with a stunning winner down the line. The former French Open champion will take on either former world No 1 Simona Halep in the semi-finals.