It was a case of so close yet so far for Warren Gatland’s charges as the Springboks came from behind to squeeze out a 17-16 victory, meaning Wales realistically can’t afford another loss if they are to reach the quarter-finals.

But that is easier said than done against a Samoan side who not only opened their New Zealand adventure with a 49-12 win over Namibia, but have also got the better of Wales in both previous World Cup clashes in 1991 and 1999.

And British and Irish Lion centre Roberts is adamant his teammates know the danger their next opponents possess, and are not taken them lightly.

"Obviously [Alesana] Tuilagi showed his quality in their first game against Namibia, in opposition 22s he's certainly a very dangerous player and he scores tries for fun," 24-year-old Roberts said.

"[Sailosi] Tagicakibau and the Pisi brothers [George and Tusi] as well are a huge threat, so defensively more than anything we need to be on the money.

"It's a huge game for us defensively and we can't afford any lapses in concentration as maybe we did last weekend, and that cost us in the end.

"We all know what Samoa are going to bring, they're a very physical team with ball in hand and physical in defence.

"Certainly they have some players who can create things out of nothing and defensively that's very hard to prepare for.

"But it's all about saving our emotion now and making sure that mentally we're right for that 80 minutes."