Brad Haddin claimed "relief" was his primary emotion after his maiden Test century against New Zealand at Adelaide Oval.

The Australia wicketkeeper Haddin has been under media scrutiny after taking over the gloves from Adam Gilchrist and had yet to make a big score in his previous 15 Test innings.

But he silenced his critics with a crushing 169 on day three of the second Test.

Haddin "trusted" his attacking game even with Australia losing two quick wickets before his arrival at the crease.

And he felt it was that instinctual approach that may have been missing during his lean last series.

"I think in India, with the bat in the back end of that tour, I started doubting myself, probably putting too much pressure on myself," he said.

"But the bottom line was I was doing all the work I could possibly do and doing all the right things off the field.

"It's probably no different to what I did in state cricket just probably the scrutiny you are under because you are on the international stage.

"I don't think it will change my mindset too much, the way I go about things, it might get you guys off my back for a couple of weeks."

The 31-year-old also fobbed off suggestions he was under pressure to emulate Gilchrist's feats of summers gone by.

"I think with that sort of pressure, it's only coming from you (the media). I've said it before, Adam is arguably one of the best players ever to play the game," he added.

"I can only trust what I do is going to be successful at Test cricket and not try to be anyone else. I think it's quite embarrassing.

"People keep mentioning Adam's name because he's one of the greats in the game and I've played half a dozen Test matches."

Making Haddin's century even sweeter was the 181-run partnership he shared with News South Wales team-mate Michael Clarke.

Clarke, who had already scored his ton, was thrilled to be out in the middle when the keeper reached his milestone.

"I'm rapt to score another Test hundred but mainly for Hads. I've played a lot of cricket for New South Wales with him, he's a very good friend of mine," said Clarke, who scored 110.

"Hads walked out to bat and every ball he hit, hit the middle of the bat. So for me, my job was easy, it was get a single and get up the other end and let him go for his life.

"Batting with your mate is a great feeling."

Haddin was dominant but did have some luck along the way. Daniel Flynn dropped a simple chance when the right hander was on 72, which Black Caps bowler Iain O'Brien admitted was costly.

"Obviously they hurt, and when a guy goes on and bats as positively as he did for as long as he did, you take 70 or 80 runs off that and it's a different scoreboard," he said.

"We would've had a few more overs with our feet up, but yes, of course catches win matches."