Luke Charteris admits Wales must raise their game ahead of Saturday's clash with Argentina.
Warren Gatland's men stuttered to a nervy and hard-fought 17-13 win over Samoa at the Millennium Stadium last Friday.
But the giant 6ft 9ins Newport Gwent Dragons believes his team-mates will have to move to another level in a bid to deliver a morale-boosting victory over the Pumas in Cardiff.
Charteris, 26, said: "The game are certainly getting harder and Argentina will be a bigger test for us but it's good.
"It's another challenge and we know we'll have to up our performance from last week. We will take the positives from the game and we played some good rugby as we did against New Zealand but made too many errors.
"But I'd much rather be here with maybe not such a good performance and a win rather than last week with a performance and a loss.
"The important thing is that we learn from our mistakes. We will look at the tape on Monday and try to improve."
Argentina arrive in the Welsh capital, fresh from a uninspiring yet narrow 16-9 defeat to England at Twickenham.
But Charteris insists the visitors will push the home side to the limit up front, especially in the scrum and line-out. He said: "Argentina are renowned for their scrummaging and I'm sure that will be hammered into us all week.
"We have to step up to meet the challenge because if we don't, we're going to come off second best. It's pretty simple for us. We've got to work hard to get the upper hand."
Charteris hopes to keep his place in the side when Gatland names his side tomorrow (Tues) lunchtime and the 16-cap star says he is enjoying his current partnership with British Lion Alun Wyn Jones.
Charteris said: "He is an unbelievable player and when you play alongside someone like that it lifts your own game to make sure you don't get left behind. If i get another chance to play alongside him again I'll be happy."
Sam Cross and Luke Treharne have been named as co-captains of the Wales Sevens side as head coach Gareth Williams names his 12-man squad to play in the first leg of the HSBC World Series in Dubai next weekend.
Bedwas head coach Steve Law and players Nicky Griffiths and Alun Rees extol the virtues of the close knit club as they prepare to host third place RGC 1404 - who are one place head of them on the Principality Premiership points table - on Saturday.
Many of the Wales squad have said Diolch (thank you) to someone who played an important part in their early playing days by nominating them to be invited to the Wales v South Africa match. One person, Gowerton Comprehensive geography teacher Mr Dean Mason was nominated by two of his former pupils, Dan Biggar and Sam Davies.
The second WRU disability rugby pilot has been delivered, this time in Caerphilly schools, culminating in a festival at the Caerphilly Centre of Sporting Excellence, Ystrad Mynach tomorrow. Plans are in place to set up a Disability Rugby Club in Newbridge to provide long-term playing opportunities.
WRU TV: Hear from inside the Wales camp as Neil Jenkins discusses this weekend's clash with South Africa and how the squad are looking to put in a strong performance to round of the 2016 Under Armour Series