Marco Jansen bowled South Africa into a dominant position as Sri Lanka crashed to 42 all out, their lowest total in Test cricket, on the second day of the first Test against South Africa at Kingsmead on Thursday.

The left-arm fast bowler took seven for 13 as Sri Lanka were bowled out in 13.5 overs – the second-shortest completed Test innings in history.

It gave South Africa a first innings lead of 149 after they had been dismissed for a modest 191 in their first innings.

The hosts stretched their lead to 281 runs when they scored 132 for three in their second innings.

Yet the 2.06-metre Jansen, one of the tallest players in international cricket, admitted that he struggled to control the ball at the start of his spell with a strong wind blowing across the ground being a "massive factor".

Having played only in eight T20 matches since returning from a three-month "conditioning break", the 24-year-old Jansen sent down a wide and a no-ball before opening batsman Pathum Nissanka had to put bat on ball.

"I struggled to get my wrist behind the ball. It felt like I was battling something but I just tried to make it work," he said.

Kagiso Rabada made the breakthrough for South Africa when he had Dimuth Karunaratne caught at first slip before Jansen, in his second over, bowled a delivery close enough to Nissanka to induce an edge to third slip.

It sparked an inspired spell. Jansen's pace and bounce, allied with the ability to make the ball swing in as a variation to his natural angle across right-handed batsmen, proved devastating.

But he still bowled another two no-balls. After at least two of his wickets he looked back anxiously at the umpire to make sure he hadn't over-stepped again.

He said, though, that once he found his rhythm, "the ball was moving nice and quickly off the pitch. We knew if we put the ball in the right areas we would always be in the game."

He said his break from cricket, ordered by Cricket South Africa, had refreshed him mentally.

"I feel I can go for longer periods of time, concentrating at a high level," said Jansen. (AFP)