George North silenced his critics with a brace of tries that saw Wales run out 22-9 winners over Ireland in Cardiff on Friday to end the visitors' hopes of a tilt at the Six Nations title.
The result means England will be crowned Six Nations champions should they beat Scotland on Saturday.
North, the strapping right winger, crossed in each half under the Principality Stadium roof at the end of a week when he was given a "warning" by the Welsh management for a poor defensive display in the recent loss to Scotland.
His second try, in the 44th minute when Ireland flyhalf Jonny Sexton was in the sin-bin, put Wales 15-6 ahead but the Irish dominated the final half-hour as they sought to keep alive realistic hopes of winning the title.
A penalty from Sexton brought Ireland within a converted try but backs-to-the-wall defence kept Wales ahead, and replacement Jamie Roberts collected a Toby Faletau charge-down to clinch victory with a 79th-minute try.
Wales rebounded from two straight losses that led to soul-searching in the country's national sport.
As for the Irish, they stayed in second place - three points behind England and a point ahead of Scotland.
Ireland conceded 10 points while Sexton was in the bin for killing the ball on his own try-line just before halftime.
The flyhalf also went off with a head injury midway through the first half.
"We knew we were one performance away from winning a game, they have been down to fine margins every week," man-of-the-match and scrum-half Rhys Webb told BBC.
"We showed glimpses of what we can do and there is more to come from us.
“You don't become a bad team overnight."
Wales captain Alun Wyn Jones added: "We owed that to the Welsh people and to ourselves. We haven't done ourselves justice in the last two games."
Irish skipper Rory Best admitted that his team, who bounced back from an opening defeat by Scotland with wins over Italy and France, were "very disappointed".
"We came here hoping and expecting to win and keep everything alive. Credit to Wales but we are frustrated with the errors we made."
RESULT
WALES 22
Tries: North 2, Roberts
Cons: Halfpenny 2
Pens: Halfpenny
IRELAND 9
Pens: Sexton 2, Jackson
Yellow card: Sexton (38')
