Ireland produced a brilliant first-half display to clinch the opening fixture of the Six Nations with a 30-22 win over Wales in Cardiff.
A dire performance from Wales in the opening 40 minutes left them with a mountain to climb in the second-half, at which they threw everything to bounce back from a 30-3 scoreline to 30-22 in an utterly dominant half.
Ireland appeared to mentally crumble under the depth of their 27-point lead, producing brilliant defence at times but unable to escape their own half as Wales pounded away at the visitors try line, falling short of cutting down the whole deficit in a classic.
Superb hands from Brian O'Driscoll built the opening opportunity for Simon Zebo to touchdown in the left hand corner for the first score of the afternoon, with Jonathan Sexton converting.
Sexton's control with the boot and sharp hands from the Irish backs kept Wales pinned back and after a set of punishing phases, Ireland were held up in the right-hand corner. Wales held out from the resulting phase of play and Sexton settled for a penalty to stretch the lead to 10-0.
Best then charged down Biggar's kick before gathering the loose ball and sending the ball wide first to Heaslip before an audacious bit of skill from Zebo saw him use his feet kept the attack going, Cian Healy pouncing from close range to leave Wales on the ropes.
Another Sexton penalty stretched the lead to 20-0 with half an hour gone, Wales imploding with another loose pass from Davies going straight into touch in the Irish 22. Healy's attempt to drive out of his 22 resulted in a penalty at the breakdown to Wales, with Halfpenny putting his side on the board.
Warburton's cheap block on Zebo handed Ireland another attacking lineout, with O'Brien setting the foundations for a final flourish in the first half. Another penalty against Wales at the breakdown yielded one more opportunity for Sexton, who slotted the kick to leave the half-time score at 23-3.
Ireland carried on where they left off at the start of the second half, a scrum on the Welsh 22 setting up a series of relentless drives before O'Driscoll clawed his way over the line from the bottom of a ruck for Ireland's third try.
A response from Wales was essential and it came through sustained drives forward into the Irish half, hard yards culminating in a Welsh lineout five metres out from the try line. A pre-planned move saw Toby Faletau held up narrowly short, before Alex Cuthbert found space between the rushing Irish defenders to score the first try of the afternoon for Wales.
Cuthbert's score seemed to light a fuse under Welsh backsides as they went for broke, Faletau storming down the left touchline before a crucial hand from O'Driscoll brought the surge to a halt.
A tap penalty sent Wales backwards rather than nearer to the line as the Irish defence turned desperate, Gilroy producing a memorable tackle on Halfpenny before Romain Poite sent Rory Best to the sin-bin for entering from the side.
The extra space was then capitalised on by Halfpenny, the full-back burrowing under the double tackle of Rob Kearney and Jamie Heaslip to score in the right corner, missing the conversion to make the score 30-15.
There was to be no let up in the Welsh response as Cuthbert thundered down the right wing, but breakdown defence from Healy was enough to relieve the pressure with a penalty.
A crucial Welsh scrum yielded a penalty for Biggar to find the corner once more, Ireland mentally struggling with the hosts resurgence. Faletau appeared initially to crash the ball against the base of the post, falling marginally short as Conor Murray was sent to the bin.
Wales were utterly dominant but unable to cross the Irish line, Davies missing a simple overlap as the green wall heroically held firm with time running out.
The hosts inevitably came again though - Craig Mitchell appearing to dive over the line before the TMO confirmed Wales third try of the afternoon, narrowing the score to 30-22.
Ireland finally relieved the pressure by pinning Wales deep in their own half to close out a brilliant opener to this year's tournament - a classic with each side forcing the other into submission for lengthy periods in each half. Ireland march on dreaming of a title. Wales have hope.
Man of the match: Streetwise, skilful, a magnificent return to form from Brian O'Driscoll stole the show in Cardiff.
Moment of the match: An outrageous piece of footwork from Simon Zebo to control possession in the build-up to Ireland's second try.
Villain of the match: Unnecessary petulance from Mike Phillips after being brought back from a tap penalty was needless.
Tries: Cuthbert, Halfpenny, Mitchell
Con: Halfpenny 2
Tries: Zebo, Healy, O'Driscoll
Cons: Sexton 3
Pens: Sexton 3
Yellow Card: Best, Murray
Wales: 15 Leigh Halfpenny, 14 Alex Cuthbert, 13 Jonathan Davies, 12 Jamie Roberts, 11 George North, 10 Dan Biggar, 9 Mike Phillips, 8 Toby Faletau, 7 Sam Warburton, 6 Aaron Shingler, 5 Ian Evans, 4 Andrew Coombs, 3 Adam Jones, 2 Matthew Rees, 1 Gethin Jenkins.
Replacements: 16 Ken Owens, 17 Paul James, 18 Craig Mitchell, 19 Olly Kohn, 20 Justin Tipuric, 21 Lloyd Williams, 22 James Hook, 23 Scott Williams.
Ireland: 15 Rob Kearney, 14 Craig Gilroy, 13 Brian O'Driscoll, 12 Gordon D'Arcy, 11 Simon Zebo, 10 Jonathan Sexton, 9 Conor Murray, 8 Jamie Heaslip, 7 Sean O'Brien, 6 Peter O'Mahony, 5 Mike McCarthy, 4 Donnacha Ryan, 3 Mike Ross, 2 Rory Best, 1 Cian Healy.
Replacements: 16 Sean Cronin, 17 Dave Kilcoyne, 18 Declan Fitzpatrick, 19 Donncha O'Callaghan, 20 Chris Henry, 21 Eoin Reddan, 22 Ronan O'Gara, 23 Keith Earls.