Rassie Erasmus was impressed with the way South Africa handled the pressure of being in "play-off mode" but said their performance in a 49-3 thumping of Italy was "not World Cup-winning standard".

The Springboks would have been facing a shock early exit from the tournament if they had lost to the Azzurri at Shizuoka Stadium Ecopa on Friday, but are on the brink of the quarter-finals after cruising to a seven-try victory.

Cheslin Kolbe claimed a double on a miserable night for Italy, who played almost the entire second half a man down after Andrea Lovotti was sent off for a dangerous tip tackle on Duane Vermeulen.

Scrums were uncontested for much of the Pool B match due to Italy losing Simone Ferrari and his replacement at tighthead prop Marco Riccioni to injury as the Springboks went top with one Pool B contest against Canada to come.

Erasmus was pleased with the manner in which his side stepped up in a must-win encounter, yet says they must raise their game if they are to lift the Webb Ellis Cup.

"This was a crunch game for us, it looked easy but it was a fairly slippery game for us in the beginning. We were a bit worried about this game." said the South Africa head coach.

"I thought the red card obviously cost them because there were stages where they almost came back into the game. I thought when they got the red card it was quite easy for us after that."

He added: "I think the boys are now in play-off mode, our team understands we are under pressure and we have accepted that and are going to live by that for the next couple of weeks.

"I guess we'll get used to that and now we go on to the next challenge. Well done to our boys, I think they handled it well.

"I think we were clinical. I thought our discipline was terrible in the first half, we conceded six or seven penalties when we were defending, but otherwise the defence was great. I think overall not a bad performance, but not World Cup-winning standard yet."