On Tuesday the four Quarter Final matches played saw three big upsets as Elise Mertens, Kyle Edmund and Marin Cilic beat Elina Svitolina, Grigor Dimitrov and Rafael Nadal respectively. All credit to the three underdogs who were all worthy winners, although the injury to Nadal is a really disappointing one for a player who has suffered too many in his career.
There is every chance we can get two new Grand Slam Champions by the end of the weekend, although Cilic and Roger Federer look the stand out candidates in the men's event. I love how Edmund has played this week with some battling displays, but that is a lot of tennis to have come through and he has not been scheduled for night sessions which means extra fatigue.
I think that Semi Final with Cilic will be a very close one, and much will depend who serves best on the day, but Edmund is feeling good. He could finish the week as the new British Number 1 and I like the fact new names have started to break through at the top of both the men's and women's games.
However I did say that the women's event has a big void to fill with Serena Williams out and I would have the American down as a big favourite to win any event she enters in 2018. It wouldn't be a big surprise if Serena comes back and dominates the remaining Slams to be played with the aura around her tough to break for the other players on the Tour. I also don't think anyone comes close to the consistency, serving prowess and power Serena Williams brings to the court and it will be a big challenge for any player on the WTA Tour to beat her.
Roger Federer win 3-0 v Tomas Berdych: There is no way Roger Federer will be overlooking Tomas Berdych considering some of the battles these two players have had over the years, but while Federer has remained at a very high level, Berdych has slipped off the top standards players set.
Berdych does really enjoy playing at the Australian Open- in terms of pure results you would perhaps say Wimbledon is the best Grand Slam for Berdych having reached a Final there, but he has reached more Quarter Finals in Melbourne. This is the seventh time in the last eight years that Berdych has reached this Round at the Australian Open so it shouldn't be a surprise that he is back here, while the wins in the last couple of Rounds over Juan Martin Del Potro and Fabio Fognini have to be respected.
A few years ago Berdych was also a huge danger to Federer. Between January 2009 and February 2013, it was Berdych who led the head to head 5-4 and regularly troubled the Swiss superstar.
However it has been one way traffic since then and Federer has moved 19-6 ahead in the head to head with eight straight wins over Berdych since February 2013. A bigger worry for Berdych has to be the fact that he has lost nineteen of the last twenty sets played against Roger Federer and last year was beaten in straight sets in both the Australian Open and Wimbledon as Federer went on to win both tournaments.
Federer has beaten Berdych four times at the Australian Open including straight sets wins in 2016 and 2017 and the numbers lean heavily towards the former World Number 1. The serve continues to set Federer up and Berdych's decline in the return numbers have really shown up against Federer in their matches against one another, while Berdych doesn't defend his serve as well as he once did.
That hasn't shown up in back to back straight sets wins and Berdych has been pretty dominant in Melbourne so far. However he has not played anyone playing close to the level Federer has reached with the latter yet to drop a set in the event and I expect a fully focused Federer to be a little too good in each set they play.
You can't ignore the long run of successes Federer has had against Berdych recently and that has to play on the mind of the Czech player. If he makes a fast start and puts a few games under the belt then perhaps this will be a match that takes a different feel, but the numbers lean heavily towards Federer and he can move into another Semi Final in Melbourne behind a strong straight sets win.
Angelique Kerber - 2.5 games v Madison Keys: The Fourth Round was a much easier day in the office for Madison Keys than it was for Angelique Kerber, but I do think this is the kind of match the latter will enjoy more than the one she faced a couple of days ago.
While Keys came out and used her power to get through the challenge of Caroline Garcia in straight sets, Kerber had to come from behind to beat surprising Su-Wei Hsieh who has bamboozled her opponents this week.
The difference in this one is that Kerber is not going to be involved in long winded rallies where her opponent is going to use slice, drop shots and plenty of movement to keep the German from finding her rhythm. Another big difference was that Kerber had to generate plenty of pace of her own as Hsieh was trying to frustrate her into mistakes and moving the ball around with accuracy to just get the Kerber mind all confused as to what was coming next.
That won't be the case against the big hitting American Madison Keys who will look to power down big serves and heavy forehands to penetrate the Kerber defences. This should mean Kerber is able to play the defensive brand of tennis which frustrated Maria Sharapova in the Third Round and also use the pace of the ball coming across to her to find plenty of big shots of her own.
The win in the Fourth Round may have given her confidence too having lost some silly matches in 2017 after a hugely successful 2016.
Keys will feel she can dictate this match on her racquet with the power she possesses, but it is all about the consistency she can produce. At the US Open Keys was able to hold herself together to reach the Final before coming apart against Sloane Stephens in that Final, but she should enjoy the conditions in Melbourne and her numbers have been very strong so far this week.
In saying that, Keys has not met someone like Kerber who has all the tools to really put her in some tough positions. Mentally it is the German with the advantage having won six of their previous seven matches including in all five previous hard court matches.
They haven't met since the end of the 2016 season, but I do like the way Kerber matches up with the Keys game and I think that is important for her here. She can frustrate Keys by getting plenty of balls back in play off the big serve and I think Kerber's defences and ability to turn a rally by using the Keys power to direct the ball back into some awkward positions will give her the edge.
Putting Keys on the move is a strong play to win the match and I like Kerber's chances to do that in this Quarter Final.
Simona Halep - 1.5 games v Karolina Pliskova: Arguably the best looking Quarter Final match across both the men's and women's event is the one between Simona Halep and Karolina Pliskova. Both players have held the World Number 1 position on the WTA Tour in the last few months, while they will both feel this tournament represents a real chance to underline that status by winning a maiden Grand Slam.
I can see both players heading into the match with the confidence of thinking they can win and move onto the Semi Final.
Karolina Pliskova has a huge serve which should be a big weapon on the faster courts that have been on display at the Australian Open. While it has been a factor in helping her through her matches, I do think Pliskova has to be even better than she has so far at the Australian Open to keep the pressure on Halep. Too many second serves or not hitting the mark with the first serve would mean Halep is able to get into the rallies and that would shift the momentum of the direction of the match.
On the other hand Halep has to make sure she gets enough first serves in to make sure Pliskova is not able to get on the attack immediately in her own service games. By doing that Halep should have a chance to move Pliskova around the court which reduces the threat from the big groundstrokes and once again would make Halep favourite to win the match.
The Pliskova return game has not been in great form over the last couple of matches which is a concern, while Halep looks like she has recovered from any lingering issues with her ankle.
It is Halep who has the mental edge having won five of the six previous matches these two have played against one another. That includes a win in Cincinnati where the hard courts have traditionally played amongst the fastest on the Tour and that should mean Halep is confident enough to get the job done in this Quarter Final.
Small factors will make big differences in the match and those are hard to read. However it does feel like Pliskova is not peaking as she would have liked going into the last eight of the tournament and I like Halep to find a way to get involved in enough rallies to wear down her more powerful opponent.
I imagine it will be a close match with very little between them, but Halep should be able to just get the better of a tough opponent. Barring Pliskova suddenly finding a huge serving day and returning to the best of her ability, Halep should have the edge.
Ultimately I can't back a player who needs to have an almost perfect day and also hope her opponent is perhaps not quite at the races in this one. With Halep dominating the previous matches, including on fast hard courts, I think she will find a way to get the better of Pliskova in an entertaining Quarter Final and move onto the Semi Final.