LUXEMBOURG - Jelena Ostapenko toppled the top seeded Elise Mertens in a close, three-set battle at the BGL BNP Paribas Luxembourg Open, coming back from a set down to win 4-6, 6-2, 6-2 and reach the quarterfinals. 

Last week’s Linz finalist, Ostapenko - who is working with new coach Marion Bartoli on a trial basis - came into Luxembourg on a tear, taking down young American Caty McNally in her opening match. She continued that momentum against the top-seeded Mertens, although the Belgian didn’t make it easy for the former French Open winner.

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“I don’t feel like I’m still at my best, but it’s much better because I know how I can play,” No.63-ranked Ostapenko said in her post-match press conference. “Obviously I won Roland Garros in 2017, so I know I can play at that level.

“But I’m getting there. Slowly, I’m getting there. Of course, I’m in a better shape now and playing better, but I think still there is so much space to improve for me.”

Ten of Ostapenko’s 14 double faults came in the rocky opening set, and Mertens took advantage of the slow start to take the lead. But Ostapenko raised her level to start the second and third sets with 3-0 leads, and stayed in control to complete the comeback after just over two hours on court. 

Mertens was in control during the early exchanges, fighting her way to four break points in the first game of the match. Ostapenko held firm, and instead drew first blood a few games later at 4-1, but Mertens stayed in the contest. She got the break back and reeled off the last five games in a row - capping it off with a blazing on-the-run passing shot to take the first set, 6-4. 

After a brief medical time out to treat pain in her left glute, Ostapenko took control of the second set with an early break to build up a 3-0 lead, aided by three Mertens double faults at the 2-0 game. The Latvian dictated the rallies with her heavy pace and flat groundstrokes, extending her advantage to 5-1. She had to hold back a late Mertens comeback charge as the Belgian hit back to make it 5-2 - but Ostapenko broke straight back to take the set. 

Ostapenko started the third set with another big 3-0 lead, staying one step ahead of Mertens and cutting down on her unforced error count. She marched ahead to the finish line, staying steady and recording a break in the final game to claim the victory after two hours and two minutes. 

“I think in the first set I had many opportunities, but I missed them when I started to rush too much. I did some unforced errors which I shouldn’t have done,” Ostapenko admitted in her post-match press conference. 

“In the second and third set I started to play more consistent, I didn’t do so much unforced errors and I was just going for the shots, playing more aggressive. So I kept more pressure on her, she was always under pressure because I was stepping in the court and playing aggressive.”

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Ostapenko fired 25 winners to 26 unforced errors against Mertens, who replied with 14 and 22 of her own, respectively. Ostapenko kept the pressure on Mertens, and was rewarded with six breaks of serve from eight opportunities, while her opponent converted just three from eight. 

Into the Luxembourg quarterfinals for the first time, Ostapenko will await a German opponent in her next match: the winner between Andrea Petkovic and Antonia Lottner.