Australia allrounder Glenn Maxwell revealed he had been eyeing up the opening position for some time after he hit a 65-ball 145 not out from the top of the order to lead Australia to a record T20 score in their 80-run win over Sri Lanka.

Maxwell had only opened twice before for Australia - once each in Tests and ODIs - and his elevation in this match in place of Aaron Finch was something of a surprise, given Usman Khawaja's presence in the side. Captain David Warner suggested Maxwell had been asked to open because Australia wished to preserve the left-hand right-hand combination, but Maxwell said he had initially floated the idea himself.

"I actually had a chat to [coach] Greg Blewett a couple of days ago after Finch hurt his finger," Maxwell said. "I said: 'Geez, I'd love to have a crack at the top of the order.' Sure enough, a couple of days, Warner gave me a tap on the shoulder and told me I was going to be up the top with him. So I was excited about it and looking forward to the opportunity."

Maxwell said he had been envious of limited-overs openers, even having recently made lighthearted fun of Finch's 18-ball fifty in the fourth ODI on social media. "Can't be that hard to do it when you've got two [fielders] outside the circle," he had tweeted at the time. Maxwell's 145 is the second-highest T20I score, behind Finch's 156 against England at the Ageas Bowl in 2013.

"I really enjoy batting at the top of the order in T20 cricket," Maxwell said. "I find it's easier to get into the innings. When you're in the middle order you have to be proactive the whole time. It seems like if you get out playing a big shot at that stage of the game, it all falls on your shoulders.

"At the top of the order you've got a little bit more freedom to get yourself into the game and play pretty normal cricket shots without taking risks. You only have to beat two guys on the fence. The way Sri Lanka set fields at the start made it pretty obvious where they're going to bowl. It made my job a lot easier in the first six."

Maxwell had reached his half-century off 27 balls, in the ninth over. He said IPL experiences - especially the 2014 IPL season when he made scores of 89, 90 and 95 twice, his previous T20 career-best - had helped him turn that start into a mammoth T20 score.

"When I looked up and there was eight overs to go and I was 80 or 90, I got the sense it would be a big score. I didn't really realise how long there was left. I think I've made that mistake a few times playing in the IPL. I kept swinging until I was out. I probably played periods a bit smarter tonight. I knew if I mistimed it, it'd go in the gap."

It has at times been a difficult year for Maxwell, who was dropped from the ODI squad completely, after a modest tri-series in the Caribbean. He had since also had poor outings with the Australia A team, for whom his high score was 46 not out in six innings across the month of August.

"West Indies was pretty disappointing," Maxwell said. "I felt like I was a bit out of luck there. I just couldn't get a break through that. To not be on the Sri Lanka Test tour probably hurt more than anything. I understood why they dropped me. I had no issues with that. And my scores were quite pitiful, by my standards, for the Australia A team. I think I scored more in this innings than in all my A team innings put together."

Maxwell's 145 is just the latest headline performance in Australia's resurgence in Sri Lanka, after they were whitewashed in the Tests. There is an argument that Australia should pick limited-overs batsmen who have had success in Asia on forthcoming Asian Test tours, but Maxwell was skeptical of that line of thought.

"To score runs in one-day cricket in the subcontinent is totally different to playing red-ball cricket, when you've got guys around the bat, five guys on the fence, and they're able to just plug away all day," Maxwell said. "It doesn't matter how many reverse sweeps for four you hit, they're still going to be around the bat. And when you try to defend, one will blow up off the wicket, take your gloves, and you're out. I know how difficult it is. People say he's made runs in the subcontinent in the white-ball form so surely he can make runs in the red-ball form. But it's just not the same.

"I'd like to think, on the back of my four-day form in Australia, I don't think it should matter where my Tests are played. I wouldn't want to be pigeonholed as a subcontinent specialist, because I know how difficult it is here. All my red-ball runs have been made in either England or Australia. On the back of that I'd like to be picked in Australia."

Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @andrewffernando