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The performance ensures he will recall his debut Test with pride and boosted his confidence after he had made just three in the first innings.

The 20-year-old said: "It was wonderful to get out there and score some runs.

"Everything was a new experience and I've learned more in this Test match than in two years of first-class cricket."

South Africa were 307 for four, leading by 164 runs at the end of Sunday's play - Smith contributed 68 runs to the total.

"We want to get to at least 400 and then have a look from there," he said.

"It's a very good batting track but it is starting to take some turn and get a bit up and down so it's not going to be easy to bat on the last day.

"If we can keep them in the field a bit longer (we can then) create a bit of pressure with our bowling.

The young left-hander said the attitude of the young newcomers to the South African side had played a significant part in raising spirits.

"I think it makes a big difference in the sense that we haven't been involved in all the defeats," he said.

"Even though we suffer with the team, we come in with a positive attitude. We've brought a bit of youth, a bit of enthusiasm - and maybe a bit of ignorance too!"