Ireland gave their Six Nations title hopes a huge fillip with a surprisingly one-sided victory over a poor Wales in Dublin.
Wales were out-hustled and out-thought from the first whistle by their inspired hosts, who led 13-0 at half-time courtesy of flanker Chris Henry's first international try and eight points from the boot of Jonathan Sexton.
Leigh Halfpenny kicked a penalty for Wales after the restart but a try from Paddy Jackson and five more points from Sexton sealed the victory.
It is the first time Ireland have started a Six Nations campaign with back-to-back victories since 2009, the year they won the Grand Slam.
And on the evidence of this vibrant display, Joe Schmidt's side will be confident of nicking a win at Twickenham in a fortnight.
Meanwhile, Gatland's tired-looking defending champions will be pleased for the extended break ahead of the visit of France, after their first away Six Nations defeat since 2011.
A spicy encounter was expected, with a lot of the pre-match coverage focusing on the apparent grudge between Wales head coach Warren Gatland and Ireland centre Brian O'Driscoll, a grudge both men denied existed.
O'Driscoll, Ireland's most capped player, was dropped by Gatland for the deciding Lions Test against Australia last summer, causing uproar in the Irish media, while several other Irishmen lost out to Welsh players in close calls.
As such, nine of the Welshmen who started that victorious match in Sydney, plus three more of the Lions touring party, started on Saturday. And it appeared to have an effect.
Sexton scored the first points of the day, slotting over a penalty after a jinking half-break by wing Dave Kearney.
There were a few worrying moments for the home faithful when O'Driscoll received treatment after a big hit by Scott Williams, who injured his shoulder in the process and had to be replaced by Liam Williams, with George North moving to centre. But the Irish talisman, playing his penultimate home Test, was soon patched up and back in the fray.
Sexton doubled Ireland's lead with a penalty from almost directly in front of the posts after Richard Hibbard was penalised for not rolling away.
When the visitors did get their hands on the ball their backs struggled to work any space and they coughed it up too easily, while the Wales line-out malfunctioned from the outset.
Wing Andrew Trimble caused mayhem in the Welsh defence with a side-stepping raid off his wing, before Rob Kearney just managed to wrestle the ball from Halfpenny following a steepling up-and-under by Sexton.
From the resulting ruck, Sexton pinned Wales in their own 22 with a cute kick and Henry rumbled over for his first international try from the line-out.
Sexton's conversion from just inside the touchline brought a huge cheer from the home fans and increased the sense of Irish irresistibility.
The fly-half missed a long-range penalty attempt on the stroke of half-time but that did not alter the fact that a ragged looking Wales had been completely outgunned in the first 40 minutes. This was especially the case at the breakdown, where Munster flanker Peter O'Mahony - the man of the match - was in dominant form.
Shortly after the restart, Sexton increased Ireland's lead with a penalty, after which Wales showed some attacking verve at last, Jamie Roberts bursting up to the Ireland 5m line. However, an infringement at the breakdown allowed Ireland to clear their lines.
Ireland captain Paul O'Connell, who missed last week's match against Scotland, was given a rapturous reception when he was replaced by Dan Tuohy after 54 minutes, at which point the heavens opened.
Halfpenny got his side on the scoreboard with a penalty but the filthy weather, and its effect on handling, scuppered any chance of a late Wales onslaught.
Sexton restored Ireland's 16-point advantage with a penalty of his own before Wales had some luck at last, the officials failing to spot that Halfpenny had nudged the ball into touch a few metres from his own try-line.
The visitors finally built up a head of steam with 13 minutes left but replacement prop Rhodri Jones was penalised for a double movement when thrusting for the Ireland try-line, and that was the last time Wales threatened.
Welsh fans were streaming for the exits long before replacement fly-half Jackson sauntered over for a try with a minute of the match remaining, the Irish pack having overpowered their Welsh counterparts with another driving maul.
Ireland almost rubbed further salt into Welsh wounds in the closing seconds after a searing break by Isaac Boss, but the defending champions' misery was already complete.
Ireland: 15-Rob Kearney, 14-Andrew Trimble, 13-Brian O'Driscoll, 12-Gordon D'Arcy, 11-Dave Kearney, 10-Jonathan Sexton, 9-Conor Murray; 1-Cian Healy, 2-Rory Best, 3-Mike Ross, 4-Devin Toner, 5-Paul O'Connell, 6-Peter O'Mahony, 7-Chris Henry, 8-Jamie Heaslip
Replacements: 16-Sean Cronin (for Best, 73), 17-Jack McGrath (for Healy, 68), 18-Martin Moore (for Ross, 54), 19-Dan Tuohy (for O'Connell, 54), 20-Tommy O'Donnell (for Tuohy, 64), 21-Isaac Boss (for Murray, 79), 22-Paddy Jackson (for Sexton, 74), 23-Fergus McFadden (for Trimble, 61)
Wales: 15-Leigh Halfpenny, 14-Alex Cuthbert, 13-Scott Williams, 12-Jamie Roberts, 11-George North, 10-Rhys Priestland, 9-Mike Phillips; 1-Gethin Jenkins, 2-Richard Hibbard, 3-Adam Jones, 4-Andrew Coombs, 5-Alun Wyn Jones, 6-Dan Lydiate, 7-Sam Warburton, 8-Taulupe Faletau
Replacements: 16-Ken Owens (for Hibbard, 61), 17-Paul James (for Jenkins, 71), 18-Rhodri Jones (for A Jones, 61), 19-Jake Ball (for Coombs, 71) 20-Justin Tipuric (for Lydiate, 71), 21-Rhys Webb (for Phillips, 79), 22-James Hook, 23-Liam Williams (for S Williams, 17).
Yellow card: Phillips (80)
Referee: Wayne Barnes (England)
Touch judges: Glen Jackson (New Zealand) & JP Doyle (England)
TV: Graham Hughes (England)