Chris O'Connell has made light work in becoming the third Australian man to make the second round of the Miami Open as he breezed to a straight-sets win over Czech Vit Kopriva.

While other Australians struggled in the big Masters 1000 tournament.on Thurssday (AEDT), Sydneysider O'Connell, who's reached No.66 in the world and is out to rise past his career-best of No.53 he achieved late last year, defeated the qualifier 6-2 6-4.

The 29-year-old battler was always in control once he broke Kopriva in the third game, going on to reel off five games on the trot against the world No.116.

Another break to love at the start of the second paved the way for O'Connell to wrap up proceedings in just over an hour and a quarter, with his only real stumbling block coming when Kopriva saved two match points as the Aussie was serving for the match.

Life will quickly get harder for O'Connell in the next round, when he faces American favourite, world No.21 Frances Tiafoe.

Of the eight Australian men in the draw, he joins the country's top pair, No.1 Alex de Minaur and No.2 Jordan Thompson, in the second round after both got a bye through to the last 64.

But elsewhere around the Miami Gardens courts, things were not looking so bright for the Aussie men's challenge, with world No.68 Max Purcell getting hammered 6-2 6-1 by Hungarian Marton Fucsovics.

A sixth defeat in seven matches continued a disappointing run for Purcell, who had a brilliant breakthrough 2023 season to reach the top-40 but who's since slumped back to No.68 in the rankings.

Another Sydneysider Rinky Hijikata, the world No 81, went down 7-5 7-6 (7-3) against Dutchman Botic van de Zandschulp.

On Friday, three more Aussies will be in action with another Sydney player Aleksandar Vukic hoping to defeat Spain's Roberto Carballes Baena for the dubious pleasure of a second-round meeting with the flying Indian Wells champ Carlos Alcaraz.

First up on the main court, Queenslander Adam Walton, the rising 24-year-old who's already battled through two tough three-setters in qualifying, has a tough ask against Canada's former top-tenner Felix Auger-Aliassime in the first round, with the winner to meet Olympic champion Alexander Zverev.

Alexei Popyrin, the Australian No.3, will face Argentine Facundo Diaz Acosta in another first-round contest.