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.
Sherfane Rutherford struck an unbeaten half-century and Gudakesh Motie produced a brilliant display of spin bowling as West Indies thumped England by 30 runs in a Twenty20 World Cup Group C encounter on Wednesday.
Australia launched their Twenty20 World Cup campaign with a commanding 67-run victory over Ireland in Colombo on Wednesday, powered by four-wicket hauls from Nathan Ellis and Adam Zampa.
Tottenham Hotspur have sacked manager Thomas Frank after eight months in charge, the Premier League club said on Wednesday, after a woeful run of results left the north London club hovering five points above the relegation zone.
South Africa survived Kagiso Rabada's final-over meltdown against Afghanistan and then a double Super Over drama before prevailing in a heart-stopping Group D match of the Twenty20 World Cup on Wednesday.
Pakistan opener Sahibzada Farhan has hit a swift half-century as the 2009 champions comfortably beat the US by 32 runs on Tuesday, clinching their second straight Group A win in the Twenty20 World Cup.