Aryna Sabalenka took a big step towards retaining her Australian Open crown by beating American fourth seed Coco Gauff 7-6 (2) 6-4 in a thriller on Thursday.
The Belarusian will meet Zheng Qinwen or qualifier Dayana Yastremska in the final.
In a rematch of their US Open title clash in September, Sabalenka and Gauff made contrasting starts as Sabalenka fired an ace and revved up her forehand to hold before pouncing on two double faults by Gauff to break.
Gauff hit back right away and the pair swapped breaks again but the 19-year-old New York champion continued to teeter on her serve, allowing Sabalenka to settle her nerves after going 6-5 down in a frantic spell to clinch the first set in a tiebreak.
The pair were locked together until 4-4 in the second set as Sabalenka countered Gauff's speed with power and the 25-year-old second seed edged ahead with a decisive break when the teenager hit a shot long before sealing victory with two massive serves.
Sabalenka will set her sights on becoming the first woman to win consecutive Australian Open titles since compatriot Victoria Azarenka in 2012 and 2013.
New Zealand overcame a blitz from centurion Harry Brook to beat England by four wickets on Sunday in the opening game of their three-match one-day international series, with Daryl Mitchell and Michael Bracewell scoring half-centuries.
Belinda Bencic breezed past Czech sixth seed Linda Noskova 6-2 6-3 to win the Pan Pacific Open title on Sunday, erasing bitter memories of her straight-sets defeat by Agnieszka Radwanska in the title clash of the same tournament 10 years ago.
Liverpool manager Arne Slot said opponents have identified a winning strategy against his Premier League champions and he needs to find a solution fast after a 3-2 defeat at Brentford on Saturday made it four league losses in a row.
Rohit Sharma hit a century and Virat Kohli a bright 74 to drive India to a nine-wicket win in the third one-day international on Saturday, sending fans home happy after what are likely to be their final appearances in Australia in their country's colours.