Wales scored two tries in each half and conceded just a pair of penalties to Argentina fly half Nicolas Sanchez to end up as comfortable winners.
Mike Phillips and George North had given Wales a comfortable 23-3 interval advantage with Leigh Halfpenny kicking 13 points.
In the second half, Wales were at their attacking best with Williams a key man at centre. It was a break from the Scarlets man from inside his own dead ball area that almost saw Wales go the length of the field for what would have been a superb score.
It mattered little though as man of the match Toby Faletau, set up by Liam Williams, added a third score with replacement Ken Owens completing the scoring.
Owens’ try would have been particularly pleasing for forwards coach Robin McBryde, a Wales line out splintering the Argentina pack as they rumbled over to score.
“I’ve been working on trying to communicate with the forwards as when they’re tired, they can be a bit lazy,” said Williams.
“But you can’t fault their effort today, they were outstanding. Every single one of them worked 110 per cent and made my job easier. We maybe left a couple of tries out there but all in all, everything went to plan.
“There is a good feeling in the dressing room but everyone is a little bit tired from the intensity of the game. The second half opened up which is what we like but it’s a little bit harder on the lungs.”
Williams was part of a back line which looked hugely dangerous at times, especiallly after the break. North’s first half effort in particular was a move straight from the training paddock while Faletau’s score followed some superb interplay between backs and forwards.
“When it opened up in the second half it was the type of rugby we all like to play,” Williams added.
“We did the hard work first defensively, wore them out and it was good to have an open game.
“It’s always nice to do what we practiced in the week. It was a great move by Mike (Phillips) and George and the one from the scrum too. The boys train hard all week and it’s good to get the result.”
One downer for Wales was a couple of more injury problems. Williams left the Millennium Stadium in a protective boot after suffering an injury to his big toe though he remains confident of being fit for Friday’s clash with Tonga. There was less positive news on Cory Allen though. Williams’ midfield partner suffered a suspected dislocated soldier, bringing a positive international debut to an early conclusion.
“It’s precautionary more than anything, the boot is just to stop my toe bending over the next couple of days,” said Williams.
“Hopefully I’ll be back on the mend on Monday and Tuesday and we’ll see how it is then. I think I’ll be strapped to the ice machine over the next few hours and into the night.
“I thought Cory was going really well up until that point and I’m pretty gutted for him obviously.”
