The out-half converted an early second half effort from RBS 6 Nations man-of-the-match Brian O'Driscoll - his 46th try for his country - and Ireland were in full control at 30-3.

Wales lifted their game over the remaining 37 minutes, putting the visitors through a huge defensive workload and gaining momentum courtesy of an Alex Cuthbert seven-pointer.

Leigh Halfpenny touched down during Rory Best's spell in the sin-bin and replacement Craig Mitchell did likewise after Conor Murray saw yellow.

But with the mercurial O'Driscoll stepping in to play scrum half, Ireland muscled their way to a deserved victory in what was a truly absorbing opening to the 2013 tournament.

Ireland quickly got into the game at the Millennium Stadium, Craig Gilroy and the strong-carrying Sean O'Brien taking on early ball and Peter O'Mahony piling forward on the left wing.

The forwards showed their intent with a well-executed lineout maul, setting the backs in motion and winger Gilroy ran out of space as he reached the Welsh 22.

Ireland continued to press with a forceful scrum and after two rucks, another priceless piece of O'Driscoll magic, allied to Rob Kearney's decoy run, released Zebo for a slick 11th minute score.

The 34-year-old O'Driscoll showed all his experience as he injected some pace on an angled run, drew in two defenders and threw a brilliantly weighted pass which caught Cuthbert out completely and sent Zebo rounding in to the left of the posts.

Sexton, who enjoyed a fine day with the boot, converted and the Irish pack upped it in the physical stakes again as Donnacha Ryan, Best and O'Brien combined to good effect in the choke tackle.

With plentiful set piece possession, Ireland went close to scoring a second try as Gilroy and O'Driscoll were held up in quick succession, the former's chance being created by a deft pass from Kearney.

A ruck offence from Aaron Shingler, close to the Welsh try-line, allowed Sexton to slot his first penalty. Wales looked shellshocked and unable to cope with Ireland's enveloping forwards and quick-witted backs, and they soon went 17-0 up.

Hooker Best raided in to block a Dan Biggar kick and collect the dropping ball, scooping a lovely pass out to Jamie Heaslip. The new captain's pass drifted behind the onrushing Zebo, but a breathtaking flick of his left boot - one of the moments of the Championship already - brought the ball up into the Corkman's hands.

Good awareness from Gilroy, close to the right touchline, kept the move going and prop Healy needed no second invitation from a close range ruck as he stretched past Mike Phillips to make the line. Sexton added the extras with a crisp strike.

By the half hour mark, Sexton had added three more points via a left-sided penalty - Ireland surging downfield on the back of an O'Driscoll turnover and a peach of a kick from scrum half Murray.

Wales showed some much-needed urgency closing in on half-time with Shingler, Jamie Roberts and George North all carrying well. Halfpenny kicked their opening points after Healy was pinged for not releasing.

Ireland had to soak up further pressure in defence - Zebo and Gordon D'Arcy putting in some vital tackles - until Best forced a penalty at a ruck close to the visitors' posts.

A late spell of attacking, with Mike McCarthy, O'Mahony and O'Brien making the hard yards, saw Sexton reply from the kicking tee to make it 23-3 at the interval.

McCarthy and O'Brien muscled in on Ian Evans to win an immediate turnover in the second half. O'Mahony followed up with a strong burst and suddenly the Welsh try-line was under threat once more.

Kearney and Murray were both denied in the right corner before O'Driscoll, showing a typical poacher's instinct, dived in unchallenged from a close-in ruck. Maintaining his 100% record, Sexton swept the conversion over for good measure.

Wales showed glimpses of their Grand Slam-winning form from last year as they upped the tempo. Justin Tipuric made an impact off the bench as they began to take the game to Ireland.

The Irish defence held out initially, but Biggar passed for Cuthbert to come from deep and break replacement Keith Earls' tackle as he touched down to the left of the posts. Halfpenny converted to reduce the arrears to 20 points.

Rob Howley's side showed better ball retention as Toby Faletau and Andrew Coombs powered forward, with space beginning to open up. Ireland racked up tackle after tackle and O'Driscoll gleaned a turnover from which Gilroy launched a kick chase.

It was a brief respite as the Welsh were beginning to get a stranglehold of possession and territory. During a frantic five-minute period, the hosts threw the kitchen sink at Ireland and O'Driscoll, Sexton and Gilroy all produced hugely important tackles in the 22.

The men in green got through an immense defensive workload, holding the Welsh at bay but Best was picked out for coming in at the side of a ruck and referee Romain Poite reached for his yellow card.

The home support raised the decibel level, recognising the improved efforts of their side. Just moments later Halfpenny got over in the right corner for an unconverted try, teed up by Jonathan Davies and Cuthbert.

Flanker O'Brien stepped in as a lineout thrower during Best's sin-binning, but Ireland were soon on the back foot. They need some excellent pieces of last-ditch defending from Kearney and Healy to keep their line intact.

The action was akin to a heavyweight title fight as both sides punched and probed in an energy-sapping series of phases.

Chris Henry, on for O'Mahony, darted from ruck to ruck and the fresh legs of the bench were needed in an attritional and intense final quarter hour.

Ireland defended heroically and with discipline on a number of occasions, scrambling back close to their whitewash with Sexton doing really well to hold up Faletau only inches from the posts.

Ireland had to soak up further punishment in defence after the loss of Murray to the sin-bin. Reinforcements were called for with props Declan Fitzpatrick and David Kilcoyne joining Henry in making their Six Nations bows. Donncha O'Callaghan also got on for cap number 91.

In Murray's enforced absence, O'Driscoll stepped in to play scrum half. Wales nabbed a third try with four minutes remaining, mauling up towards the line and then prop Mitchell plunged over from a metre out. Halfpenny's conversion cut the lead to eight points.

Composure was called for in the 14-man Irish ranks and this game of two contrasting halves ended with Ireland pinning Wales back, the leadership of the likes of Heaslip, O'Driscoll, Best and Henry shining through.