Cardiff Blues prop Ben Warren expects another physical battle against world champions France after Wales U20s triumphed in the perfect dress rehearsal.

Gareth Williams’ young guns kicked-off their World Rugby U20s Championship against hosts Argentina yesterday and fought to an impressive 30-25 victory in Rosario.

Warren was one of four Cardiff Blues young hopefuls involved in the encounter, with the tight-head prop receiving particular plaudits for his powerful forward display.

Up next is an even bigger test against reigning champions France on Saturday and Warren has called on his teammates to gear up for another full-blooded encounter.

He said: “The boys dug in really well and worked as a unit – the full 28. The 15 that started the game were superb and the boys that finished the game were even better.

“Argentina were very big boys and we knew going into the game that they have a dominant pack so we worked hard over the last few weeks and made sure we set our height low.

“We dealt with it well and I don’t think we got as much out of it as we should have. Now we’ll regroup and get ready for France, where hopefully we can get another win.”

Wales fell to a 32-10 defeat to France in the Six Nations but were in the encounter for 60 minutes before Les Bleus demonstrated their champion quality.

And Warren insists Wales will learn from their mistakes as they look to maintain their momentum in the global showpiece.

He added: “We have looked back at that game and will learn from our mistakes. We know they will be big and physical, like Argentina, but we’re tight as a group and we will dig in for each other.

“We have to be confident after that win but there’s a lot of things we can work on. We’ll look back at our set-piece, our lineout and I don’t know much a lot back play, but we’ll regroup and go into France.”

Warren was joined in the Welsh pack by Teddy Williams, the son of Cardiff RFC legend Owain, who came off the bench at the Racecourse.

The Ysgol Gyfun Gymraeg Glantaf pupil is currently undertaking his A-Levels and sat a chemistry exam at a local school hours before kick-off.

It is one of three exams the versatile forward will take during the Championship and he rushed across the city in the nick of time, again impressing.

He added: “It was a good win to kick-start our tournament. We knew they were going to be a physical battle but it’s a good win.

“The atmosphere was exactly as we expected. They are an emotional, passionate country so we knew what we were getting into.

“We’ve got over hurdle number one, now all attention turns to France and we need to get a win there if we want to progress.

“It’s a really together squad, we have good strength in depth and if a few boys pick up injuries we have players who can come on and make a difference.”