Miami Open: Wozniacki holds to defeat Niculescu in straight sets 

Caroline Wozniacki had a tight finish to her match but found a way to hold it together at the Miami Open on Saturday. Monica Niculescu found ways of being tough in the match, including a serious scare in the second set tiebreak that gave the Dane a 6-4, 7-6 (4) win on Grandstand Court at Hard Rock Stadium.

The series between the pair is vast and have all ended the same way, a Wozniacki win. While one was a simple withdraw from the Romanian, she has only challenged the Dane once in Madrid two years ago - where she won four games but crucially failed to take the third set. Niculescu wouldn't let previous history bother her as she proved as much against Garbine Muguruza, winning in three sets on Friday to record her fourth successive win.

With nothing strong coming from her game at Indian Wells, the former world number one was aiming to add a second with comfort and dominance against the 31-year-old. She didn't have a clean opening service as Niculescu challenged the 13th seed but failed to capitalise on an AD point. Instead matching Wozniacki with a solid service hold, she soon found herself trailing.

Wozniacki's fast start an important one

The fourth saw the Dane take control of the score, reaching break point to lead 3-1. A major gear change for the 28-year-old saw her breeze beyond her opponent - beating Niculescu with great returns before a rush back for control allowed her to cap the sixth game with her name.

Wozniacki answered back with a huge serve to love getting her settled in a baseline rally before the 31-year-old moved in for the Dane to nail the return behind her. With the three-game margin back in Wozniacki's hands, she fought for the set but went to deuce as Niculescu refused to go down early. She hung on through the two breaks played to extend her time and inch closer to a possible tie - doing exactly that, having figured out how to counter Wozniacki's aggressive forehand and break her in the ninth.

With one to go and the serve in her end, the 31-year-old fell behind on serve as Wozniacki smashed way to secure the break needed to take the set after 56 minutes. The serve was in check, landing nearly 60% of points with 13 winners to go - while Niculescu drew 18 errors, although getting winners on the second serve was important in keeping relative pace with the former world number one.

Niculescu chipping away as match contin

Wozniacki's defence was good enough to race into a two-game lead in the second set, too. Niculescu found a way to break back in the third, forcing her way to deuce before clinching the game's only AD point. They went through the next four games holding serve as Wozniacki remained ahead 4-3. When she gained the break to serve for the match, the 13th seed fell behind three break points and despite saving one with a line-drive winner, she ultimately blew her chance for a comeback.

The break gave Niculescu a shot at tying things up in the tenth, avoiding an early conclusion and prompting the serve it out question too. Answering Wozniacki's returns with amazing court coverage, she was able to hold serve and press on. A key hold saw Caroline find the right moment to score winners, who ultimately contained the 11th game and went for the break to end Niculescu's faint hopes.

The 12th game was a dramatic one for the Romanian, who challenged two calls and lost one of them. Wozniacki had gotten to 30-all, leaving the door open for a moment - but Niculescu executed the next rally well with a sharp cross-court shot to earn a game point opportunity.

Losing it with a drop shot, she played the next point beautifully to gain the AD point and score a clear winner to set up the tiebreak. Just when everything was going well, she committed three consecutive errors to provide Wozniacki a great position - forcing a fourth point with a line winner followed by a cross-court effort to lead 5-0.

The Dane's serve was a huge stance which put Niculescu under intense pressure, before hitting the ball long to gift her a whopping six match points. Despite saving four in quick succession, she was unable to pull off the comeback as Wozniacki got the ball on the line to end the late thriller in two hours and eight minutes.

She had done it! @CaroWozniacki overpowered Niculescu 6-4, 7-6(4).#MiamiOpen pic.twitter.com/fLHAjGRPVb

— WTA (@WTA) March 23, 2019

"I thought I started off well," Wozniacki said after the match. "I started off aggressively and came to the net quite a few times and all of a sudden I just lost my rhythm a little bit.

That's what she does so well mixing up the pace giving drop shots and lobs. You think the point is done three times and still not done and, in the end, I just lost my rhythm a little bit and just had to hold tough."

She's set to take on Hsieh Su-Wei next in the last-16, who took down world number one Naomi Osaka in three sets.