Steve Smith admits he has been overwhelmed by the emotion of his return to Test cricket.

The former Australia captain, who was removed from the role and banned for a year for his part in the ball-tampering scandal of last year, became only the fifth Australian to hit centuries in both innings of an Ashes Test as his side moved into a commanding position on day four at Edgbaston.

England have been left chasing 398 to win, or more likely bat out the final day to claim a draw.

Smith scored 142 in the second innings and he said his first-innings hundred had brought a very emotional reaction.

"It did overcome me a little bit and I had to take a few breaths," he told Sky Sports. "It's really special and I'm really grateful to be back playing Test cricket.

"I love playing Test cricket and I love playing against England. It's a terrific place to play Ashes cricket.

"It feels like Christmas morning every morning getting to come and do this."

Smith underwent elbow surgery in January before his ban had expired, and the 30-year-old admitted it led to doubts over whether he would return at all.

"There was a time when I didn't know if I wanted to do it again," he said.

"Just before I had my elbow brace taken off I just wasn't sure if I had it in me. Funnily enough, the day I had my brace taken off, I was like, 'right, I'm ready to play again'.

"I'd never felt like that about cricket in my life. They were strange feelings and emotions but now I'm back enjoying what I'm doing and practicing hard. To be playing for my country and wearing this cap, I'm really honoured and grateful.

"It's incredibly special. Obviously I've been out of the game for a while. I was a little bit nervous coming into the first day.

"Normally I don't get too nervous before a game and it was nice to get that hundred away in the first innings.

"I've never scored hundreds in both innings before in any form of cricket so I was pretty keen to do that and I was fortunate that things went my way today and I was able to help us get in a good position."

England batting coach Graham Thorpe said the hosts needed to play confidently on Monday despite the difficult situation they are now in, with the pitch likely to prove difficult for Australia's bowlers just as it was for England.

"The pitch has changed," he said. "It's taken a lot of turn but for the seamers it's got a lot slower. Our seamers found it hard. We know there's a lot of turn out there and facing Nathan Lyon is going to be a challenge tomorrow.

"But it was a good start tonight and the chat in the dressing room was to get out there, put some partnerships together and try and bat long."

"I think you still have to have good intent to score. We've played in games where you don't feel you can win the game but you've still got to keep your intent to score runs because then you move better, your feet move better and you feel better.

"That's why it's important to put partnerships together. Don't think too far ahead, but certainly try to score runs because that gives you confidence."