AUCKLAND, New Zealand – No.5 seed Caroline Wozniacki continued her winning start to 2020 as she moved through into the quarterfinals of the ASB Classic thanks to a hard-fought 6-1, 4-6, 6-4 win over Lauren Davis.

Already through to the semis of the doubles, in which she is partnering Serena Williams, the Dane, who will retire after the Australian Open, took two hours and 20 minutes to eliminate the 2017 champion.

READ MORE: 'I got myself in a hole but I got myself out' - Serena survives McHale in all-American Auckland clash

In both previous meetings between the players, Wozniacki, the WTA World No.39, had recorded comfortable successes, most recently at the China Open last October, but she was made to work harder on this occasion.

"I got a little lucky in the end and it could have gone both ways," she admitted. "She’s a great player and she fought very hard today but so did I. 

"When you’re playing well and your opponents played well, and you push each other to play at a high level. Those are the fun matches to play."

The first set proved to be a one-sided affair as the 29-year-old did not allow her opponent to hold serve even once, though the American found her rhythm in the second and deservedly extended the match. The deciding set proved to be the most entertaining of the encounter, but it was the Dane who ultimately prevailed.

Wozniacki, a two-time runner-up in Auckland, was dominant in the opener. She successfully managed to extend the rallies and was able to wait for error from her opponent to take the upper hand.

Three break points were created in Davis’ first service game, and while she was able to save two, the third was converted, setting the tone for the first half hour of the match.

Wozniacki’s persistence was highlighted by her comeback from 40-0 down on the Davis serve when leading 4-1. She ran through five successive points to seal her third break of the match, though getting over the line to seal the opener proved complicated as she finally took it on her fifth set point as Davis pushed a passing shot wide – her 19th unforced error of the set.

Those mistakes that had been costly in the first set for the WTA World No.63 began to dry up in the second as she started to find her rhythm, particularly on the backhand side, which yielded regular winners.

The first seven games of the set went in favor of the server before Davis was able to make the breakthrough in a thrilling game in which she crafted a 15-40 lead only to be drawn back to deuce. A short backhand winner, though, brought up a third chance that was not missed.

Though she then opened a 40-15 lead as she served for the set, Wozniacki’s stoicism came to the fore as she saved both points then fought successfully to break back.

Davis, however, managed to retain the momentum and aided by a kind bounce off the net, she broke Wozniacki for a third time to draw level.

"She played some really great points at the end of the second set and that was that," the Dane admitted.

READ MORE: Auckland 2020: Friday's Order of Play and Match Points

The best tennis would be saved for the decider, and most notably after a Wozniacki mishit had seen her fall 3-1 behind.

The former WTA World No.1 broke back immediately to love, sealed by a sparkling crosscourt backhand winner, then after holding her own serve she grabbed the initiative, quelling a succession of fine groundstrokes from Davis and responding with some aggressive hitting of her own.

An uncharacteristically loose game from Wozniacki followed as Davis drew level once more, but the 2018 Australian Open champion made her decisive play to move 5-4 ahead, producing the type of gutsy points that took her to the very top of the game.

A simple hold of serve booked a repeat of the 2018 final against two-time defending champion Julia Goerges, who has yet to drop a set this year.

"She’s a good player, big server, big forehand. She’ll try to be aggressive. I’ll just have to play well myself," Wozniacki concluded.

2020 Auckland Highlights: Wozniacki fights past Davis