Captain Sam Warburton insists Wales now have to treat the World Cup as a straight knockout competition following their 17-16 defeat to South Africa.
Following the dramatic defeat Warburton says Wales have no choice but to win their remaining four Pool D games.
"It's like a knockout competition," he said. "You can't really think any other way than you have to win your games.
"Everybody knows how important the game is on the weekend. Obviously the win against Samoa is a must."
Wales' display in defeat against the World champions was hailed by many, with Warburton named man of the match.
But the 22-year-old flanker chose to reserve a special mention for his back-row colleagues Dan Lydiate and Toby Faletau.
"I though Dan and Toby were fantastic," said the Cardiff Blues player.
"For Toby to be 20-years-old playing at number eight in one of the most physical positions in the game - I think it's unbelievable to see him put in the performances he is at the moment.
"I'm thoroughly enjoying playing with Dan and Toby at the moment and hopefully those two can keep up their performances for the rest of the tournament."
Despite his own performance Warburton said he would have swapped his man of the match award for a victory over the Springboks.
"I've always aspired to try to be a good player and the World Cup is the perfect opportunity to try and do that.
"I gave absolutely everything on the weekend. Unfortunately we didn't get the win but I was satisfied with my performance.
"But I'd swap my man-of-the-match [award] for a win over the South Africans any day."
And the narrow defeat has persuaded Warburton that Wales should be looking to shake off their underdog tag.
"I'd rather have the tag of being expected to win and people wanting to chase you," he said.
"Everyone in the squad would rather aspire to be the better team rather than the underdog.
- For the latest on the 2011 Rugby World Cup in New Zealand visit our breaking news and gossip page.