Serena Williams continued her impressive start to 2020 with a straight-sets win in the Auckland quarterfinals on Friday.
Trailing 1-3, 0-40 in the second set, Williams clicked into gear to beat Laura Siegemund 6-4 6-3 and advance to the semifinals.
Joining her in the final four in Auckland was Caroline Wozniacki, who followed Williams onto Stadium Court and dispatched defending champion Julia Goerges for the loss of just five games.
Wozniacki’s 6-1 6-4 win sets up a semifinal against Jessica Pegula, who progressed past an injured Alize Cornet.
Williams, meanwhile, will face the winner of Friday night’s quarterfinal between in-form teenager Amanda Anisimova and the resurgent Eugenie Bouchard.
Following that match, Williams and Wozniacki will team up in doubles, playing for a place in the final against Belgian duo Kirsten Flipkens and Alison Van Uytvanck.
The duo – both Australian Open champions and former world No.1s – have been a popular drawcard in Auckland in their first appearance together on the doubles court.
The last time Williams was the top seed at a singles tournament was in Auckland 2017 – the year she went on to win the Australian Open three weeks later.
On Friday, she battled windy conditions and a tenacious opponent before completing victory in just under 90 minutes.
It marked her third straight win in the New Zealand capital, after beating Camila Giorgi and Christina McHale earlier in the week.
"I am definitely not super comfortable. I am trying. I would do a little bit better if I wasn't hitting every shot in a conundra of wind. I got a little negative in the end. It was just so windy,” said Williams, who has a 24th Grand Slam singles title in her sights at Australian Open 2020.
"It was good for me to fight. She stepped up and hit a lot of good winners. It was not easy.
“I had to step up and play a little better and get through it."
Wozniacki, meanwhile, advanced to just her second semifinal since April last year following a win over Goerges, who had won six of their 10 career meetings.
The Dane, ranked No.1 as recently as February 2018 but down to 39th due to an ongoing battle with rheumatoid arthritis, announced Australian Open 2020 would be her last professional tournament.
With her form encouraging in Auckland, she could be set to go out on a high in Melbourne.
“I've been serving really well this week, so I hope it can continue," Wozniacki said.