AUCKLAND, New Zealand - It may have taken them over a decade of playing on the same tour to team up, but Serena Williams and Caroline Wozniacki are making up for lost time, battling into the ASB Classic final in their first tournament together with a 7-6(9), 6-2 defeat of Kirsten Flipkens and Alison Van Uytvanck - after saving five set points in a nailbiting first set.

It is Williams's first doubles final since winning Wimbledon 2016 with elder sister Venus, and just the second doubles final in her career with a partner other than Venus, following her Leipzig 2002 title alongside Alexandra Stevenson. For Wozniacki, the drought has been even longer: the Dane had not reached a doubles final in nearly 11 years, since winning Memphis 2009 with Victoria Azarenka, and it is just her fourth doubles final overall.

Nevertheless, the former singles World No.1s have spent this week ploughing through more experienced doubles teams - and today, needed to draw on all of their champion qualities to overhaul Flipkens and Van Uytvanck, who were also bidding for their first final as a pair.

Williams and Wozniacki asserted their authority straight out of the blocks, with the American in particular swatting away volleys and returns with ease as she propelled her team into a quick 3-0 lead after a break of the Flipkens serve.

Gradually, though, the Belgian duo worked their way back into the match. Taking advantage of Wozniacki's inferior net play, they directed as much traffic towards her as possible whenever she was in the forecourt; by contrast, once Flipkens settled into her groove the 34-year-old showed off exquisite touch at net, finding winning angles repeatedly with feathery finesse.

It made for a rivetingly tight set: seven of the final eight games of the opening act would go to a deciding point. During this passage of play, the Belgians seemed to have wrested the momentum after capturing the Williams serve twice to move up 5-4 - but they were unable to get over the line, despite both serving for the set.

This would ultimately be due to a combination of their own nervy errors and Williams's ability to rise to the occasion with her back to the wall. The Belgians squandered two set points with Flipkens serving at 5-4, with Van Uytvanck tapping a putaway volley into the net before Flipkens double faulted; two games later, having broken Wozniacki to get another crack at serving the set out, Williams crunched a forehand winner to save a third.

An epic tiebreak - which featured the most spectacular rally of the match, a rat-a-tat net exchange involving all four players eventually won by Van Uytvanck - saw both teams carve out multiple opportunities, only to be denied. Williams and Wozniacki overhauled a 2-4 deficit to hold the game's first three set points - only to see them flash past after Flipkens came up with an ace and a volley winner, and a Wozniacki backhand found the net.

The Belgians couldn't make the most of their escape, though: Williams fired back with an ace of her own to save a fourth set point, and when Flipkens double faulted again on their fifth, that would prove their final chance. A Wozniacki service winner sealed a crucial opening stanza on her team's fourth set point.

Williams again excelled as she pressed home her team's advantage in the second set. A phenomenal get on deciding point to break Flipkens in the third game had the crowd roaring, and it was the American who again pounded away a backhand volley winner to capture the Flipkens serve again for 5-2 and a double break.

The Belgians would have one shot at clawing their way back into the match - but Flipkens would miss the kind of forehand volley that otherwise been her strength today on deciding point on the Wozniacki serve in the fourth game. There would be no further opportunities as the big-name team maintained the pressure, Wozniacki serving out victory at the first time of asking by sending a backhand winner through the middle.

The final weekend of the tournament could be an intriguing one for both Williams and Wozniacki. Their opponents in the doubles final will be either Asia Muhammad and Taylor Townsend or Coco Gauff - who missed an opportunity to play Williams in a popcorn singles clash by one round - and Catherine McNally; meanwhile, the pair also remain on course to collide in the singles final, having booked their places in the semifinals earlier.

2020 Auckland Doubles Highlights - Serena and Wozniacki seal final spot