'Been a long day': Ruud through at Australian Open with 1am finish

Norwegian second seed Casper Ruud battled through to the Australian Open second round on Tuesday as he kicked off a campaign that could see him become world number one.

The 24-year-old ground down Tomas Machac of the Czech Republic 6-3, 7-6 (8/6), 6-7 (5/7), 6-3 on Margaret Court Arena in a match that finished after 1:00am.

He will next play American Jenson Brooksby who toppled Australian Christopher O'Connell.

"It's been a long day," said the world number three Ruud, whose build-up suffered an unexpected blow when he lost his first match at the Auckland Classic warm-up tournament.

"I'm very eager to hopefully have a good tournament and this was a good start, a tough one.

"Tomas played well, very aggressive, but I was able to come back and stay strong towards the end, so very happy," he added.

Ruud missed last year's event with an ankle injury, but recovered to enjoy a breakthrough 2022, reaching the final of both the French and US Opens.

He had a chance to top the rankings when he took on Carlos Alcaraz in the Flushing Meadows final, but the Spanish teenager won in four sets to take the title and with it the number one spot.

Alcaraz is not in Melbourne as he nurses an injury and three players could take the top ranking from him by lifting the trophy.

They include Serbian superstar Novak Djokovic, Greek third seed Stefanos Tsitsipas and Ruud.

According to the governing body ATP, Ruud can also become world number one by simply reaching the final, as long as neither Djokovic nor Tsitsipas win the title.

If none of those scenarios play out, the reign of Alcaraz will continue.