The margins are so tight in this competition that there was stunned silence in Stadio Zaffanella last night as Wales raced into a 19-0 lead after just 15 minutes.
It was a disastrous start for Ireland as Wales punished them with a ferocity which they could not match and it seemed like a damage-limitation exercise before the end of the opening quarter.
Last year Ireland won two matches and finished fourth, this time round they could finish eighth having also won two games. Such tight margins don't allow for falling 19-0 down inside quarter of an hour.
Wales have held the edge over Ireland since the U-20 grade was created in 2008, winning six of the 11 clashes prior to this. They had met three times previously in the World Championship, with Ireland winning just one of them, while the most recent meeting was in the Six Nations where Wales won 19-12 in Colwyn Bay.
Ireland needed a good start in their bid to respond to that defeat but they were on the back foot from the start as Wales ruthlessly punished them from the outset.
A break off a midfield scrum created the opening for Wales as Ireland struggled to get tackles in and full-back Dafydd Howells, who made his senior debut against Japan last year and clocked up 11 appearances for the Ospreys during the season, raced through to score.
Wales made every chance count and No 8 Harrison Keddie showed good hands down the left to feed outside him where Seb Davies made the overlap, with Jarrod Evans converting to make it 12-0 after just nine minutes.
Ireland were struggling in their set-piece and regular knock-ons undid a lot of hard work, and they were left with a mountain to climb when Wales made it 19-0 after just 15 minutes.
Ireland captain Josh Murphy seemed to be obstructed in midfield but Wales made the opportunity count and left winger Joshua Adams scored after being put through by Howells.
Moments earlier, Ireland had a chance to get off the mark but Joey Carbery was unable to land the penalty from 35 metres on the right wing.
Ireland finally managed to string some phases together and laid siege on the Welsh but while their flanker Tom Phillips was binned as they desperately defended their line, Ireland could not get over.
Wales, having rarely got out of their half while down a man, extended their lead after Phillips came back, with Evans tapping over a penalty to make it 22-0 approaching half-time.
Ireland were given some hope after the restart when Sam Arnold broke from deep and while Nick Timoney was caught by Howells in the left corner, Ireland recycled well and Ringrose sent Gaffney over in the right corner.
Carbery added the points and Ireland were given further hope when Welsh captain Ollie Griffiths was binned for a high tackle on Carbery towards the end of the third quarter.
Ireland managed to put pressure on the Welsh set-piece and they were rewarded with a try off a scrum into the final quarter, with scrum-half Charlie Rock getting the touchdown to reduce the margin to 22-12.
Ireland needed to get within a score before the dying moments but could not find a way through.
And so a tournament which promised so much after two opening wins will fizzle out in Viadana on Saturday when they clash again with the Scots to decide who finishes seventh.
Ireland - C Gaffney; S Fitzgerald, G Ringrose (J Owens 72), S Arnold (F Cleary 72), J Stockdale; J Carbery (T Quinlan 78), C Rock; A Porter (L O'Connor 78), S McNulty (A McBurney 43), O Heffernan (C O'Donnell, h-t); D O'Connor, A Thompson; J Murphy, C Oliver (L Dow 53), N Timoney (R Moloney 53).
Wales - D Howells; EW Benham, G Smith (J Thomas 39), O Watkin, J Adams; J Evans (D Jones 44), T Williams; L Garrett (K Bale 54), L Belcher (T Myhill 72), D Lewis (J Jones 78); S Davies, A Beard; T Phillips, O Griffiths, H Eddie (R Elias 64).
Ref - W Houston (Australia)