Wales Under 20 fly-half Matthew Morgan claimed 19 points and Liam Williams scored two tries as their Junior World Championship campaign began with a bonus point win over Argentina U20.
Morgan scored the opening try and kicked four conversions and two penalties in Padua.
Argentina replied through scrum-half Marcos Bollini, but Wales wing Eli Walker crossed after the break.
Walker gave Williams the scoring pass for his second.
Brian Ormson kicked a penalty for Argentina, but they could not find an answer to Wales' attacking play orchestrated by Morgan, who kicked four conversions and two penalties.
Wales take on defending champions New Zealand in Rovigo on Tuesday, 14 June (1710 BST) followed by hosts Italy in Treviso on Saturday, 18 June (1710 BST) in Pool A.
The winners of the three groups and the best runner-up advance to the semi-finals.
Wales head coach Richard Webster said: "We are pleased with how the game went, our game-plan worked well.
"We still have areas in which we can improve, and we will have to up our game for New Zealand."
Wales: Steve Shingler (London Irish); Liam Williams (Llanelli), Owen Williams (Blues/Cardiff), Lewis Robling (Dragons/Newport), Eli Walker (Ospreys/Swansea); Matthew Morgan (Ospreys/Swansea), Jonathan Evans (Dragons/Newport); Rhodri Jones (Scarlets/Llanelli), Kirby Myhill (Scarlets/Llanelli), Will Taylor (Ospreys/Swansea), Macauley Cook (capt, Blues/Cardiff), Cory Hill (Blues/Pontypridd), Edward Siggery (Pontypridd), Luke Hamilton (Blues/G Wanderers), Ben Thomas (Ospreys/Bridgend).
Replacements: Lewis Smout (Blues/Pontypridd), WillGriff John (Blues/Pontypridd), Lloyd Peers (Ospreys/Bridgend), Owen Sheppeard (Blues/Pontypridd), Lewis Jones (Pontypridd), Rheon James (Scarlets/Carmarthen Quins), Iolo Evans (Scarlets/Llanelli).