Tim Paine is proud of the way a youthful Australia team dismantled Sri Lanka in the first Test in Brisbane, but knows they are still "not anywhere near the finished product".

Pat Cummins claimed 10 wickets in a Test for the first time in his career as Australia completed an innings-and-40-run victory inside three days, dismissing Sri Lanka for 144 and 139.

Debutant Jhye Richardson also impressed with five scalps across the match, while Marnus Labuschagne (81) and Travis Head (84) were chiefly responsible for Australia reaching 323 in their only innings.

"Seven of our 14 players were 25 or under and I thought the way we went about it was excellent, particularly our bowling group," said the hosts' skipper Paine in a post-match news conference.

"I just said [to the team], if we execute like that with the ball and field the way we did, we'll have success against a lot of teams on a lot of different surfaces.

"Any Test team that you can beat in three days, it's a huge effort. For a young group it's really pleasing.

"No doubt it will do confidence the world of good, but we're not anywhere near the finished product. We're a long way off where we want to be. We've still got some work to do in all departments."

Paine hailed the "outstanding" discipline of Cummins and Richardson, describing the former as "relentless with his line and length".

However, it was another frustrating Test for the out-of-sorts Mitchell Starc, who returned match figures of 2-98, though Paine is backing the left-armer to regain his best form.

"We've known for a long time what we're going to get with Starcy. Sometimes he can be a little bit erratic, but when he's on he's literally the best in the world," Paine added.

"We're pretty confident that his best is not too far away. He's going okay. He's working really hard. I've seen him doing quite a bit extra than what I have in the past, so clearly he knows he's not at his best. He's working hard to get that.

"Anyone in any level of cricket goes through some times when it doesn't go your way and it's a bit harder than what it has been. Mitchell Starc is the type of bowler who is one wicket, one spell away from being devastating again, so we're hopeful that's really close."