MATCHES TO WATCH ON DAY FOUR OF THE AUSTRALIAN OPEN

* Serena Williams (USA) v Lucie Safarova (CZE)

A rematch of the 2015 French Open final, won by Williams in three sets. Williams is 9-0 against Safarova over the journey but their head-to-head record belies the danger that the power-hitting Czech poses.

* Marcos Baghdatis (CYP) v Rafael Nadal (ESP)

The popular Cypriot returns to Melbourne Park for another big-time showdown, 11 years on from his fairytale run to the final. In his way this year is a steely Nadal, who showed form above his ninth seeding in his first-round dismissal of Florian Mayer.

* Naomi Osaka (JPN) v Johanna Konta (GBR)

The upwardly mobile Brit takes on next-gen wonderkind Osaka in a battle of game styles sure to attract plenty of attention. Konta’s title-winning form in her birthplace of Sydney caught the eye of the tennis world – just as Osaka’s run to a tour event final in Tokyo last year showed her capacity.

* Alexander Zverev (GER) v Frances Tiafoe (USA)

Two emerging talents collide when 19-year-old Zverev plays 18-year-old Tiafoe for a place in the last 32. Zverev’s ability was on display against Roger Federer in the Hopman Cup, while Tiafoe’s world ranking of 108 at such a tender age shows his potential. This might be the first meeting between the pair but who knows where the rivalry might end.

* Benoit Paire (FRA) v Fabio Fognini (ITA)

Two of tennis’ biggest firebrands meet in a battle of the heavy hitters and swollen egos. Fognini flamed out of the Open last year after breaking racquets, swearing and more than one fight with a chair umpire. Paire is one of France’s most volatile characters, with a Wimbledon meltdown on his CV.