"It didn't start great, my first over in Test cricket went for 14 [12]," he said ahead of the Sydney Test against Australia on January 4. "I haven't really thought about it yet or reflected but it's gone way better than expected. Couldn't have asked for a better start, I guess."

At the Gabba, Jansen struck with his first ball in Australia when he had Marnus Labuschagne caught at slip on his way to figures of 3 for 32. In Melbourne, his final return of 1 for 89 did not reflect how well he bowled, particularly a spell to Steven Smith on a sweltering second day.

Jansen revealed he did not realise the problems he was causing Smith until Kagiso Rabada spoke to him in the middle of his spell.

"Think KG came to me and said, 'listen, Marco, keep going because he's not looking comfortable'. Think that was after my third over bowling to him," Jansen said. "I didn't even recognise that he was, not struggling, but finding it a bit challenging and only after that I could see that I should shy away, keep going, keep going, hitting the hard length.

"For me, I always try and see moments and if I see a moment I go even harder in that moment. Whether that's with the ball, in the field or with the bat. So after KG came to me, that's when I realised that I can't just bowl a floater here, I have to keep on him because we might take a wicket."

In Sydney, South Africa are looking to avoid a series whitewash and keep alive their slim hopes of qualifying for the World Test Championship final. In a theme consistent with what captain Dean Elgar has said throughout a difficult tour, Jansen insisted it was not a lack of skill that had left South Africa a distant second best, particularly at the MCG where they were beaten by an innings and 182 runs. Instead, he believes it's the ability to seize key moments.

"It's making that mental shift and making a conscious decision to say I'm going to put my hand up and do whatever it takes to influence the team in a good way or get the team over the line," he said. "Personally for me, I know everyone gives their best, it's trying to figure out what we can do as individuals to influence the team in a good way or influence the game.

"For me, I always try and see moments and if I see a moment I go even harder in that moment."

"Whether that's taking five blows to the body or bowling that seven-eight overs on the trot, sort of recognising the moment and doing whatever you can in your power to help the team into a good position.

"We have three Tests left until the final, obviously we want to win all three to give ourselves the best chance possible to get into the Test Championship final. So it's not like we are only going into this game thinking it's just another game and we cruise through it, there's still a goal, still a purpose."