MIAMI, FL, USA - No.13 seed Caroline Wozniacki continued her dominance over the always-crafty Monica Niculescu, taking down the Romanian in two sets, 6-4, 7-6(4) to move into the fourth round of the Miami Open.

In doing so, Wozniacki extends her head-to-head lead over Niculescu to a perfect 10-0, with 19 of the 21 sets contested going the Dane’s way.

“I’m just happy to be through in two sets, she’s such a tough opponent and doesn’t give a lot of rhythm,” Wozniacki told after the match. “She gets a lot of balls back too. I’m just happy with the way I felt out there and pleased to be through.”

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The No.13 seed came into Miami in search of victories, after being sidelined for two months due to viral illness. Wozniacki scored her first win since the Australian Open against Aliaksandra Sasnovich in her Miami opener, recording a solid 6-4, 6-4 result.

The 2017 finalist continued her run against Niculescu, staying solid against the Romanian’s signature slices and dropshots. Niculescu came into the matchup full of confidence after stunning Garbiñe Muguruza in the last round, but it was Wozniacki who earned the first break at 3-1. The Dane attacked the returns, and dodged four break points from Niculescu who was looking for a quick break back.

Wozniacki found herself under pressure once again while trying to serve out the set at 5-3. Niculescu pressed the Wozniacki serve, bringing up three break chances even as Wozniacki worked her way to set point. Finally Niculescu converted on her fifth opportunity to get them back on serve. But Wozniacki stayed solid as always, and replied in kind in the next game to take the set on a break.

The same pattern unfolded in the second set, with Wozniacki finding an early lead and Niculescu fighting her way back in it. The pair traded breaks twice: Wozniacki getting ahead 2-0 and Niculescu breaking straight back, and once again with Wozniacki closing in on the set at 5-3, and Niculescu breaking straight back to send them into a tiebreaker.

Wozniacki played a nearly perfect tiebreak to reel off six points in a row - but that’s when Niculescu found another level. She pulled from her bag of tricks, and her tricky employed slices and dropshots to save four match points, looking poised for an improbable comeback. But Wozniacki slammed the door shut just in time, closing out the match in straight sets.

Up next, Wozniacki will take on another crafty player when she faces No.27 seed Hsieh Su-Wei in the fourth round. Hsieh completed a three-set stunner to take down World No.1 Naomi Osaka, coming back to win 4-6, 7-6(4), 6-3.

“I think I started off really aggressively and felt the ball really well, but then she just basically broke my rhythm,” Wozniacki assessed. “I’m very happy with the way I kept fighting and just kept my head relatively cool.

“I think with every match you get more and more used to the conditions here in the new site.”

Read more: Hsieh shocks Osaka to reach Miami Open fourth round

“Hsieh and Niculescu are probably the most alike opponents that you can have on tour,” Wozniacki joked. “But Hsieh will definitely be another tricky opponent. Great hands, mixes up the pace, takes away time from your shots.”

Wozniacki leads Hsieh 4-0 in the pair’s head-to-head record, with all but one encounter being won in straight sets.