Brian O'Driscoll hopes his battered body does not betray him as be embarks on a potentially career-defining six months that began in virtuoso fashion with Ireland's 30-22 victory over Wales.

O'Driscoll opened the RBS 6 Nations with a Man of the Match performance headlined by the genius that created the opening try for Simon Zebo, but also notable for his own touch down and a frenzied shift in defence.

With the Lions travelling to Australia this summer and the captaincy up for grabs, it was an immaculately-timed reminder of his enduring brilliance that left opposite number Jonathan Davies - a rival for selection at outside centre against the Wallabies - outclassed.

Bookmakers reacted by promoting the 2005 Lions skipper to favourite to lead the tour after he had started the day third in line behind Sam Warburton and Chris Robshaw.

O'Driscoll has conceded this may be his last Six Nations and yesterday he left the Millennium Stadium with blood coating his nose and his left ear marked by several stitches.

Ankle surgery resulted in his absence from Ireland's autumn campaign, while shoulder and hamstring problems have troubled him in the past, and he admitted that fitness and not desire will determine his future.

"Who doesn't like Man of the Match? They are few and far between these days, but when they're there you enjoy them," he said.

"The big thing is trying to be fit and getting as close to 100% fit as you possibly can when you take to the pitch.

"I felt good against Wales, my ankles both felt good, as did all the other bumps and bruises.

"If you can start games that way you have every chance of putting in a half decent performance."

"The captaincy doesn't make any difference, I still see myself as a leader in the team and helping Jamie out where I can" - Brian O'Driscoll

Wales assistant coach Shaun Edwards described O'Driscoll as "the difference between the two teams" while Ireland coach Declan Kidney declared "the bottom line is you would love to have the guy around forever".

But having witnessed a pulsating championship opener in Cardiff that consisted of an almost-uninterrupted second half of defensive bravery from the Irish, Kidney sounded a note of caution over the inevitable physical toll.

"If you look at the performance he put in, that's not easy on the body," Kidney said.

"Huge credit to him, given the amount of game time he has had, to come out and give such an international class performance like he did."

Kidney's decision to relieve O'Driscoll of the Ireland captaincy - a post he has held with distinction since 2004 - and award it to Jamie Heaslip was widely debated before the Six Nations.

It could yet prove a masterstroke, inspiring a reaction from a player able to concentrate on his own game, even if the Leinster centre insists his role remains the same.

"The captaincy doesn't make any difference, I still see myself as a leader in the team and helping Jamie out where I can," he said.

"You don't play any differently if you're captain, you always try to lead by the way you play."

An entertaining opener in Cardiff saw Ireland establish a 30-3 lead two minutes after the interval, only to then spend the rest of the afternoon hurling themselves at the resurgent Welsh.

O'Driscoll's ability to fix three defenders with a burst of speed, run into space and well-timed offload that sent Zebo darting over was matched by an outrageous piece of skill from the Munster wing himself.

With Heaslip's pass heading for the turf, a sprinting Zebo backheeled it with his left foot into his hands to carry on a move that ended with Cian Healy crashing over.

"Simon has got a striker's potency, likes to finish tries and his skill level for the second try was a joke, keeping the ball up with his foot," O'Driscoll said.

"It's nice to watch and nice to have those guys on your team rather than playing against them.

"Zeebs is a very a skilful guys - he's good with a soccer ball. He's playing with a lot of confidence and you have to be if you're doing things like that in your first Six Nations game."

Arguably the championship's most entertaining fixture delivered once more and it is Ireland who enter the second weekend - England visit Dublin on Sunday - with a spring in their step.

"It was a very physical game, real Six Nations stuff which you expect when you come to Cardiff," O'Driscoll said.

"We'd lost the last three to Wales and we just felt as though we needed to stop the rot.

"It's a great day, a good start for us in this Six Nations. It puts us in a good place with England to come next week.

"This championship's about momentum. If you lose the first you're in trouble, if you win you're in a good spot. We have to build on this.

"The understanding from winning the Grand Slam in 2009 is that even when you're not great, you have to be good. Consistency will be the key for this Six Nations."