Federer has not dropped a set so far in the 2018 tournament, dispatching Aljaz Bedene, Jan-Lennard Struff, Richard Gasquet and Marton Fucsovics without any undue effort.
The Swiss is likely to be tested by Berdych, although the Czech is on an eight-match losing streak against Federer that stretches back to 2013.
Berdych dropped sets in each of his opening matches, to Alex De Minaur and Guillermo Garcia-Lopez, but has since beaten seeds Juan Martin del Potro and Fabio Fognini.
Express Sport brings you all the latest action from Melbourne.
Roger Federer vs Tomas Berdych LIVE
(* denotes next to serve)
Federer 7-6, 2-1 Berdych*
9.45am: Federer is still not serving as we know he can, but that forehand is starting to fire. He has to save another break point in the third game but fires himself up when a series of fine groundstrokes gets him out of trouble.
9.30am: Something, something, winning ugly. Sign of a champion? Sign of THE champion, if you ask me. After a pretty ordinary set by his standards, Federer immediately earns the mini-break with a beaut of passing shot and makes it two a few seconds later with some powerful baseline hitting. He takes a 5-1 lead into the change of ends.
He has five set points and converts the very first with a sumptuous drop shot. Remarkable.
9.25am: This is unreal. Federer has looked a million dollars until now and he looks about $12.50 today. Two double-faults in the game hand Berdych a second set point, although he does find some excellent defence to save it.
He finally holds, after missing a simple forehand at game point previously. We’re going to a tie-break.
9.10am: Controversy! Federer forces two break points, his first of the match, but Berdych finds a big serve. Federer challenges but Hawkeye appears not to work – the umpire tells the players the call was good, even though the system can’t display the graphic.
Federer gets into an argument with the umpire about it, pretty needlessly, and loses the next point as well. He forces one more break point from deuce that he can’t take, and then saves a set point with a killer backhand return.
Seconds later, he plays a wonderfully aggressive point to get a fourth chance to break back – and he does! Federer is awake at last.
9am: Federer produces his most convincing hold of the match, doing so to 15, but he has yet to make an indent on the Berdych serve, which he will have to do if he is to avoid dropping this first set.
8.55am: Rod Laver Arena is in shock. Federer is playing like a drain. Two double-faults already, a first serve percentage of just 59 and he’s only won one point on second serve. He misses an easy volley at 15-30 on the Berdych serve too. That was an opportunity he has missed by a distance.
8.40am: Right, we’re up and running on Rod Laver Arena. Federer is a little bit grumpy so far because he’s lost a couple of points, ever the perfectionist, and has to save a break point early on. Berdych then batters a backhand return when down advantage and when the Swiss nets a forehand, there is a second break point – which he converts! That wasn’t in the script.
8.30am: Berdych has won the toss and will serve. Bit rare that these days – most players like to receive first.
8.15am: “Rafael Nadal is out. Surely this is Roger Federer’s to lose?” I hear you cry.
You’re not wrong, reader. You’re not wrong.
Federer, already an overwhelming favourite for the title, now has to beat Berdych, unseeded Hyeon Chung and either Kyle Edmund or Marin Cilic to retain his Australian crown.
Simples, right?
Well, we’ll see just how simple in about 15 minutes when Federer and Berdych take to the court.