The hosts dominated the first half and led by 17-0 at the break thanks to tries from Dan Sheehan and James Lowe. A penalty try for Wales and yellow card for Ireland's Tadhg Beirne just after halftime threatened to make things interesting.
Ireland were a lot more ragged in the second half and the game remained competitive until Ciaran Frawley marked an impressive first start with a debut try on 67 minutes and Beirne added the bonus-point try at the death as Wales sank to their 10th defeat in their last 11 Six Nations game.
"You're always chasing an immaculate performance but we know we're not going to do that every time... You don't turn your nose up at five points in this competition," Ireland captain Peter O'Mahony said in a pitchside interview.
While the second half and another high penalty count may disappoint coach Andy Farrell, Ireland's start was familiar as they looked to use the ball at lightning speed while snuffing out any Welsh possession.
The visitors' high defensive line held firm for 20 minutes to keep the deficit to three points in the face of 75% Irish possession, but the dam broke on the 21st with an opening try that also had a ring of familiarity.
Having just lost his first Irish lineout this year, hooker Sheehan used the next one to attack the line with the help of almost all his teammates and crashed over to stretch his lead as the Six Nations top try scorer with his fourth in three games.
Against England, Wales did not give away a single penalty in the first half. In Dublin, they conceded eight in the first 27 minutes alone, while Ireland would eventually concede 13 to Wales' 12 in total.
Ireland's patience was rewarded with a second try on 31 minutes as Lowe was afforded the easiest of finishes thanks to a perfectly timed offload from fellow wing Calvin Nash.
Wales put the Irish defence under some pressure before the break and again just after halftime, resulting in the penalty try and 10 minutes in the sin bin for Beirne.
It was the first points Ireland had conceded in 150 minutes of Six Nations rugby and while they resumed control for most of the period down to 14 men, they had to survive a couple more tilts at their line as Beirne returned.
Ireland thought they had put things out of sight on the hour only for a Bundee Aki try to be chalked off. Frawley did just that seven minutes later.
The bonus point looked a bridge too far when a second Irish player, replacement lock James Ryan, received a yellow card late on but Beirne finished off multiple phases to make it 15 points from a possible 15.
"I think the scoreline probably doesn't reflect it but Ireland outmuscled us and that's probably the difference between the two sides at the moment," said Wales coach Warren Gatland.
Ireland travel to England in two weeks before hoping to play for their second successive grand slam at home to Scotland on March 16th. Wales have back-to-back home games against France and Italy, with the latter now a potential wooden spoon decider.
