Kerber's exit from this year's Australian Open at the hands of Coco Vandeweghe - served as a warning to Serena Williams ahead of todays 4th round clash against the crafty Czech, Barbora Strycova.

Plan B

The rhythm of the first set was upset early on, as Serena lost her serve in the very first game, only to break back straight away and set the mood for the rest of the set. Something was amiss with Serena's often reliable first serve. Strycova unsettled the world number 2 and had umpteen chances to draw clear in the opening set. A still not 100% fit Serena hung in there and eventually managed to close out a scrappy first set 7-5.

Serena did a great job of reverting to plan b, using her double-handed to keep the ball in play and move Strycova, who was holding her left thigh gingerly at one point, around the court.

Taking control in the 2nd set

Serena, still recovering from injury herself, having had very little competitive match time this season, warmed to the task earlier in the 2nd set to break serve and take a 3-1 lead. A shocking first serve percentage of 48%, by the American's phenomenal standards anyway, meant that Serena did not seize the initiative as easily as she ruthlessly as she normally does in this position, but did not look in great danger after this and closed out the match for a 7-5 6-4 victory.

Not at her best, but not dropped a set

With the Konta fans getting excited about the form of Britain's number 1, it is worth noting that Serena, despite being anywhere near her best, has yet to drop a set. Not wanting to rain on Konta's parade, but if Venus William's can overcome a stoic and tricky Anastasia Pavlyuchenkova, in her quarter final.

Then the mouthwatering prospect of a Serena v Venus final, could very well be on the cards. This would be some spectacle!

Is Stefi's record about to completely go?

Much has been made of the fact that Serena is tied with Steffi Graf on 22 open-era Grand Slams. Serena must be sick of being asked about it. Against Strycova today, you could tell that Serena was playing with something on her mind, but she still has more than enough in her locker to get the job done. Can she do so for three more matches? You'd be unwise to bet against her.