Victoria Azarenka rolled back the years at the Australian Open on Tuesday as the two-times champion crushed third seed Jessica Pegula 6-4 6-1 to reach the semi-finals and remain on course for her third Grand Slam crown.

Victory marked the first time in a decade that the 33-year-old had made it to the last-four at Melbourne Park and she will make her first appearance in a major semi-final since the US Open in 2020 where she went on to lose in the title clash.

"Well, it hurts to beat her because I always want her to do well, but the same time I know I have to play my best tennis," Azarenka said of her friend and practice partner Pegula.

"She's been playing amazing, very consistent and I knew from the first point I have to bring it.

"We had so many rallies and I wanted to try to stay there, take opportunities because she was going to take everything if I don't try to win myself and I'm very proud that I executed my game plan really well."

Azarenka, the last woman to defend the Australian Open title after her 2013 triumph, played superbly to race into a 3-0 lead over American Pegula in the first set before the highest seed left in the women's draw finally held serve.

Pegula found her rhythm playing closer to the baseline and controlling the rallies to break back, but Belarusian Azarenka found another gear to move ahead in the contest before both players failed to hold serve in the next.

Former world number one Azarenka took the decisive lead, however, and closed out the match to set up a semi-final meeting with Wimbledon winner Elena Rybakina after the Kazakh 22nd seed beat former Roland Garros champion Jelena Ostapenko.

Wimbledon champion Rybakina eased into the semi-finals of the Australian Open with a straight-sets victory over Jelena Ostapenko.

As expected between two of the biggest hitters on the women's tour, this was first-strike tennis, but Rybakina was the steadier in a 6-2 6-4 victory on Rod Laver Arena.

Both had caused upsets in the previous round, Rybakina defeating world number one Iga Swiatek and Ostapenko powering past Coco Gauff.

The Latvian, French Open champion in 2017, was through to her first grand slam quarter-final for nearly five years, but produced too many errors to put any real pressure on Rybakina.

The Kazakh number one, who is edging closer to the top-10 position she would have occupied had Wimbledon offered ranking points, broke serve to open the match and was 3-1 ahead when a heavy shower caused a delay and led to the roof being shut.

Rybakina maintained her momentum on the resumption to take the first set and, although Ostapenko, who again continually complained about the accuracy of the automated line calling, opened up a 2-0 lead in the second, she could not hold onto it.

Almost three-quarters of the points were decided within four shots while Rybakina's serve, the best in the women's game following Serena Williams' retirement, yielded 11 aces and was a key difference between them.