Australian Open semi-final predictions: Can anyone stop a Nadal v Djokovic final?

The 2019 Australian Open has reached the business end, with the men's and women's singles tournaments into the semi-final stage. The women's final takes place on Saturday before the men's on Sunday, but who will reach the title matches at Melbourne Park? Jon Turner takes a look at the various match-ups and predicts which players will be competing for the title this weekend. Whatever the outcome of this encounter, Greek star Tsitsipas has already secured the performance of the tournament after his stunning four-set win over defending champion Roger Federer . This was by no means a fluke result from a plucky underdog: instead it felt like a coming-out party for one of tennis's next big stars. Tsitsipas, 20, followed that performance with a fine win over in-form Roberto Bautista Agut to reach this stage, and given his sky-high confidence levels and undeniable talent, he will no doubt back himself to go all the way. On Thursday, the 14th seed will take on by far his biggest challenge of the tournament against a 17-time grand slam champion in blistering form. Nadal, the 2009 Australian Open champion, has made a mockery of the fitness doubts surrounding him ahead of the tournament to steamroll his way to the semi-finals. This should be a thrilling, high-quality contest, but Nadal's relentlessness will eventually wear down Tsitsipas. Prediction: Nadal to win in four sets It's been some tournament for 28th seed Pouille, who has defied the form guide to reach the semi-finals. The Frenchman entered the tournament having failed to win a single match this season, going 0-3 at the Hopman Cup before losing in the first round of the Sydney International. Now he stands on the cusp of a first grand slam final. The draw may have been kind to Pouille in the first week, but wins over Borna Coric and most recently Milos Raonic were real statements that the 24-year-old should not be taken lightly. However, on Friday he faces a test like no other at Melbourne Park - the top seed and six-time Australian Open champion Djokovic. The 31-year-old Serb may have dropped sets in previous rounds to Denis Shapovalov and Daniil Medvedev, but he has largely looked ominous in his pursuit of a record seventh title. Can Pouille find a way to through the iron-clad Djokovic game? As good as the Frenchman has been in Melbourne, the gulf in class and size of the occasion will be too much this time. Prediction: Djokovic in three rather comfortable sets There are unlikely runs at grand slam events, then there is Collins's run at the Australian Open. Here is a player who had previously never entered the main draw at Melbourne Park - her best effort came last year when she reached the final round of qualifying. She is now, quite incredibly, one win away from the final. Collins's conquests en route to the semi-finals have been rather impressive, with world No 19 Caroline Garcia and the talented Anastasia Pavlyuchenkova both falling to the American. But it was her 6-0, 6-2 dismantling of world No 2 Angelique Kerber that stands out as arguably the performance of the tournament. Collins's fighting qualities have played a huge part in her march to the semis - she looked down and out after the first set against Pavlyuchenkova - and she will need to call on them again when she faces a red hot Kvitova on Thursday. Eighth seed Kvitova is on a 10-match win streak, losing just one set in that time against Ashleigh Barty in the Sydney International final. The Czech has been simply unstoppable, and Collins will need to produce something even more special to extend her stay at Melbourne Park. Prediction: End of the road for Collins as Kvitova wins in straight sets On paper, the other three semi-finals should go the way of the pre-match favourite. This is much harder to call. US Open champion Osaka is continuing her meteoric rise on the WTA Tour, and is two wins away from holding the two most recent grand slam titles. The Japanese world No 4 has arguably not even played her best tennis in Melbourne, yet has still reached the semi-finals. She has proven - at the US Open and Indian Wells - that she is a player for the big occasion, and is sure to raise her game on Thursday. Pliskova, meanwhile, enters the match after staging the most remarkable of comebacks to beat Serena Williams in the quarter-finals. The Czech's blend of heavy hitting and calmness under pressure are the sort of attributes that will serve her well against Osaka. Two powerful, attacking players going toe-to-toe should make for an exhilarating contest, but Osaka's superior athleticism should give her the edge - as long as she keeps her emotions in check. Prediction: Osaka in three tight sets

Australian Open semi-final predictions: Can anyone stop a Nadal v Djokovic final?

Ahead of the semi-finals at Melbourne Park, Jon Turner predicts who will reach the men's and women's singles finals