Will Greenwood admitted he owed his England team-mates a try after his bizarre error almost gifted South Africa a crucial edge in their pool match.
The prolific centre pounced on Lewis Moody's charge-down of Louis Koen's kick for the only try of England's 25-6 victory.
It was his 28th in 43 Tests, moving him to within two of Jeremy Guscott's record of 30 for an England centre.
But earlier, with England leading 6-3 approaching half-time, Greenwood inexplicably forgot to touch a dead ball down behind his own line.
Referee Peter Marshall ruled a forward pass as Greenwood hurled the ball towards Jonny Wilkinson for a 22 drop-out, conceding a five-metre scrum.
Kyran Bracken managed to force a turnover but England still conceded a penalty that Koen landed to level the half-time scores at 6-6.
"I had quite an eventful day," Greenwood admitted. "After not putting the ball down behind our own sticks I was happy to make up for that with the try.
"I cocked up basically. It was an aberration but there were no recriminations from the guys and fortunately we turned the ball over at the scrum.
"For the try, Lewis Moody had the energy and enthusiasm to close down on their number 10 when he looked as though he had time to clear.
"The ball bounced nicely for me, and then it was just a case of not messing
Greenwood insisted there was no air of panic at half-time, despite a first-half display riddled with uncharacteristic errors.
"There were a lot of old heads in there who have been in those situations before," he explained.
"We just said we had to stick to what we knew well, hold on to the ball and the points would come."
Greenwood's centre partner Mike Tindall admitted that despite their delight in victory, the side are intent on improving on a scratchy performance.
"It is a massive boost to beat South Africa by a comfortable margin in the end," said the Bath centre.
"But it wasn't pretty and we didn't play that well, so there is a lot to work on."