The quarterfinals are underway at Melbourne Park, as rumours abound about Jannik Sinner's health ahead of his clash with Alex de Minaur. Follow live.

American Danielle Collins is out of the Australian Open following a straight-sets defeat by fellow countrywoman Madison Keys.

The American rallied from a set down to reach the last four in Melbourne for the third time, and will face No. 2 seed Iga Swiatek next.

Lorenzo Sonego will take on American Ben Shelton in the other men’s quarter-final on Jan 22. Read more at straitstimes.com.

As much as any top player, Sinner has been able to expose De Minaur’s lack of first-strike weaponry. The Aussie’s strength is his scrambling and counterpunching, but Sinner serves too well, hits too hard, places the ball too precisely for his defense to be effective. De Minaur hasn’t found a way to hurt, rattle, of disrupt him.

Iga Swiatek’s latest lopsided win at the Australian Open came via a 6-1, 6-2 score in the quarterfinals against No. 8 seed Emma Navarro on Wednesday. The No. 2-seeded Swiatek not only has not dropped a set so far in the tournament,

No. 19 seed Madison Keys scored the big upset on Day 9 of the Australian Open, defeating No. 6 Elena Rybakina 6-3, 1-6, 6-3 at Margaret Court Arena to advance to the tournament quarterfinals.

Alex de Minaur is through to the quarterfinals of the Australian Open for the first time, defeating American giant-killer Alex Michelsen.

That man was Novak Djokovic, the 10-time Australian Open champion, who got lucky to snare a set. They met only once more last year - the Shanghai final - and Sinner did the legend over again. That is the quality of the player de Minaur was trying to take down.

Keys raised her game, though, breaking Svitolina in both the final sets while staying rock-solid on serve. Shelton, the 21st seed, is the last American in the men's singles draw, having carried on after the third round demise of US Open runner-up Taylor Fritz and the quarterfinal exit of 12th seed Tommy Paul.

MELBOURNE: Defending champion Jannik Sinner raced into the Australian Open semifinals on Wednesday in imperious fashion after Iga Swiatek was