Melbourne Park, 4 December 2012 | Natalie Yoannidis

Weather conditions, a knee injury and a rampaging opponent could not derail the Optus 18s Australian Championships campaign of No.1 seed Nick Kyrgios on the first day of the main draw.

The world No.4 junior progressed to the second round following a 6-4 7-5 win over Victorian Aaron Addison.

It was not all smooth sailing for Kyrgios who trailed 2-3 in the first set before a trainer was called to the court to inspect a nagging knee injury.

In spite of the concern, the 17-year-old continued to play aggressive tennis, winning the next three straight games to take a 5-3 advantage in the first set.

> Photos: Optus 18s Australian Championships

Rain threatened to wreak havoc in the match as players were forced off the court for over an hour, disrupting any momentum Kyrgios had obtained from the earlier break of the Addison serve.

The top seed was not deterred by the pause in play, picking up from where he left off and closing out the first set on serve 6-3.

The second set appeared to be heading in a similar direction as Kyrgios appeared to be in a rush, not even stopping for a rest at the completion of the first set.

But Addison, who only yesterday earned his spot in the main draw through qualifying, refused to lie down, adopting a defensive style of play to surge to a 5-2 lead.

Kyrgios, who came close to upsetting now No.1 ranked Australian male Marinko Matosevic at the Australian Open Play-off last year, was growing frustrated and had a few words to himself, but the No.1 seed managed to regain his composure, forcing the break before producing two magnificent aces in his own service game to level the score at 5-5.

He completed the comeback by winning the next two games to claim the second set.

Speaking after the match, Kyrgios confirmed he had struggled through the game due to injury.

“It was obviously a bit tough, I was getting a bit of a knee injury and I came out a bit flat but I think I picked it up towards the end so it was good,” he said.

“Unfortunately it’s [the injury] not something that can heal in a couple of days, it needs a bit of a rest for a couple of weeks. I’m just going to have to ice it and hope it feels alright for tomorrow.”

In other matches today Victorian Marc Polmans upset seventh seed Harry Bourchier in a hard-fought three-set encounter 6-4 4-6 6-2.

The deciding set consisted of desperate rallies from the back of the court.

Eventually Polmans secured the all-important break in the second game and did not look back, taking out the final set 6-2 over his more fancied opponent.

Second seed Thanasi Kokkinakis progressed to the next round following an impressive 6-1 6-0 performance against New South Welshman Matthew Tanza.

Eighth seed Blake Mott also had a solid win over Victorian Daniel Guccione 6-4 6-2.

Rain disrupted afternoon matches, you can check updated results, draws and order of play here.