Two-time Australian Open champion Victoria Azarenka has turned back the clock to stun world No.3 Jessica Pegula in straight sets and tee up a tantalising semi-final against Wimbledon champion Elena Rybakina.
Azarenka, the 2012 and 2013 Open champion, defeated close friend Pegula 6-4 6-1 to reach the final four in Melbourne for the first time since sealing back-to-back triumphs 10 years ago.
"It hurts to beat her (Pegula) because I always want her to do well," Azarenka said.
"She's been playing amazing, very consistent and I knew from the first point I had to bring it.
"I just wanted to try to stay there, take opportunities because she was going to take everything if I don't try to win myself. I'm very proud that I executed my game plan really well.
"It's so amazing to be in the semi-final of another grand slam."
Plenty has changed for Azarenka in the 10 years since her last semi-final in Melbourne - she is now 33 and a mother, but her aggressive baseline play was a reminder of her past triumphs.
The Belarusian said her impressive Australian summer was reward for taking a fresh approach to her pre-season.
"Last year my tennis wasn't bad but I wasn't there mentally to go out there," she said.
"I played with a lot of fear and anxiety and it really was difficult to be brave and to make the right choices in the important moments when you feel anxious, when you feel hesitant.
"I worked a lot on my mindset and challenging myself on my things I wouldn't really do before and tried to push myself forward."
The upset means all of the top-four seeds - Iga Swiatek, Ons Jabeur, Pegula and Caroline Garcia - have failed to reach the semi-finals in Melbourne while world No.5 Aryna Sabalenka is the only top-20 player left.
No.22 seed Rybakina earlier easily accounted for 17th seed Jelena Ostapenko 6-2 6-4.
Pegula, 28, hadn't dropped a set in Melbourne before facing Azarenka and had appeared primed to kick on and reach a semi-final at a slam for the first time.
But Azarenka worked over the American while Pegula struggled to get her serve going as she made a third straight quarter-final exit at Melbourne Park.
Azarenka raced away to a 3-0 lead in the first set but struggled to close it out, requiring five set points across three games to claim it as Pegula found a foothold in the match.
But the Belarusian needed just 33 minutes to cruise through the second set and seal an ultimately comfortable victory.
"That was a tough match. She played at a high level the entire time," Pegula said.
"I felt like every time I tried to get a little bit of momentum, I just wasn't able to really grab a hold of it."
