SINGAPORE - Caroline Wozniacki said a more assertive approach is fueling her spectacular start to the WTA Finals after she thrashed world No 1 Simona Halep in straight sets on Wednesday.

The 27-year-old stunned Halep 6-0, 6-2 in just 63 minutes in Singapore to storm into the last four of the year-end tournament for the loss of just four games.

Wozniacki, a renowned counterpuncher, said she has enjoyed playing a more aggressive game in the round-robin format.

"Even if you lose the first match, you still have nothing to lose," said the Dane.

"It's just a nice cushion to have. I think that kind of motivates me to start off strong and just go for it.

"I just ran a lot of balls down and I played aggressive and I mixed up the pace. Everything I wanted to do was going my way."

Wozniacki feels well suited to the slower court of Singapore, where she was a semifinalist in 2014.

"I think this court is great for the all-round player, who can play both aggressive and defense," she said. "I just have been feeling good and am playing at a high level."

It was a bitterly disappointing evening for Halep, who was impressive in her opening victory over Caroline Garcia.

"I made too many mistakes and she didn't miss," Halep said. "It was one of my bad days. During the points I missed too many and I wanted to over-hit the ball."

In the other match of the evening, world No 8 Garcia kept her Finals bid alive with an epic three-set victory over Elina Svitolina on Wednesday.

Garcia said she is working on keeping her emotions in check after crying during her hard-fought victory.

Down 5-3 and on the brink of elimination, Garcia dug deep and reeled off four straight games to prevail 6-7(7), 6-3, 7-5 in two hours and 44 minutes in Singapore.

It was a stellar comeback from Garcia after blowing two chances to win the first-set tie-break.

An emotional Garcia went back to her chair and started crying before receiving a pep talk from her coach and father Louis-Paul Garcia.

Garcia said the disappointment of losing the set was overwhelming. "I didn't handle it very well," she said after the match.

"I was pretty frustrated about losing the first set, and I was trying to come back and just forget about it."

The 24-year-old admitted her fragile temperament can often be detrimental to her chances on court.

"I play with my emotion and sometimes it is just too much," she said. "Sometimes you have to just let it go and keep going."

Garcia rebounded to claim an impressive fighting victory, having been in severe danger in the third set.

"I tried to be even more aggressive when I was down 5-3 ... I went for it," she said. "I was more accurate. I was patient on the long rallies, and that makes all the difference, just waiting for the opportunity to hit the right shot."

Agence France - Presse