BBC Sport analyses the key battles that will decide Saturday's match in Cardiff.

One knock-on ended a good break but Morgan was solid defensively and provided good support in attack, taking his try well after Tom Shanklin's break.

After an injury-ravaged career, it was no more than Morgan deserved for his resilience. Has ensured Wales have not missed injured captain Gareth Thomas.

Murphy started shakily and put one chip ahead straight into touch, but grew in stature as Ireland threw caution to the wind, claiming their second try late on.

Williams failed to take the right option on one occasion when Wales had numbers out wide, but always showed a willingness to stretch the Ireland defence.

Also did well defensively to force Anthony Foley into touch 10 minutes into the second half when an Ireland try might have caused some anxiety.

Dempsey was also held up short in the first half when he seemed destined to score, emphasising the lack of Irish cutting edge in attack.

Shanklin stood up superbly well to the challenge of facing O'Driscoll, having one of his best games for Wales.

He continually made the hard yards in attack with a series of thrusting breaks, creating the second Welsh try for Morgan.

The Ireland captain did his best to inspire his troops but was well shackled by some superb Welsh tackling and conceded an unnecessary penalty.

Wales' pin-up boy had his best game since the opening win over England, keeping his cool to land an early drop goal and thumping over a 52m penalty from inside his own half.

His defence was also inspiring and only a silly attempted trip on Geordan Murphy as he scored Ireland's second try blotted his copybook.

Maggs ran straight and hard as ever but rarely troubled the Welsh defence and was exposed by Shanklin for the second Wales try.

A late replacement for the unfortunate Rhys Williams, Taylor had a solid game, supporting Wales' attacks and keeping his head in defence.

He combined with Stephen Jones to stop Girvan Dempsey scoring in the first half, after a searing break from Hickie.

The Irish wing didn't quite have the pace to finish the break himself, and may be left sweating on a Lions place.

Jones continued the superb form he has shown throughout the campaign, totally overshadowing the substituted O'Gara.

After missing his opening kick at goal, Jones landed his next five and weighed in with some thumping tackles, cementing his status as the Lions fly-half-elect.

O'Gara had a miserable day, having his kick charged down for the first Welsh try and conceding a penalty for rushing up too quickly in defence.

Appeared to lose his cool when he argued with the referee and was hauled off to be replaced by David Humphreys early in the second half.

Peel further enhanced his reputation with a second successive man-of-the-match display, showing a cool head throughout.

Quick tap penalties kept Ireland on the back foot and is now in pole position for the Lions number nine shirt.

Stringer had a nervy start and put one kick straight into touch, and only started to ask questions of the Welsh defence when it was too late, like many of his team-mates.

Odds on Jenkins scoring the opening try must have been long, but the prop did superbly well to charge down O'Gara's kick, kick ahead and dive on the ball.

Also performed his set-piece duties well and put in some big hits in defence.

Hayes worked hard and was solid in the scrummage but like the rest of his pack, otherwise struggled to exert himself on the game.

Davies missed a few of his jumpers at the line-out but otherwise had another effective game before being replaced by Robin McBryde 10 minutes from time.

Byrne's line-out work was proficient as usual but struggled to get into the game in the loose exchanges.

One of a number of ageing Irishmen whose days may be numbered, he was replaced by Frankie Sheahan just after the hour.

Jones was penalised once at the scrummage after Corrigan drove him up upwards but otherwise held his own in a strong Welsh scrummaging effort.

Jones was replaced by John Yapp late on but can be content with another solid outing.

The veteran Corrigan may have played his last Test as another who struggled to make an impact, emphasised when his replacement Marcus Horan showed up well in the final quarter.

Sidoli drove strongly into the heart of the Irish defence but conceded a penalty for holding on and got involved in an unnecessary fracas with Paul O'Connell.

O'Kelly put in his usual work-rate and provided plenty of good line-out ball but got little change from the Welsh forwards in the tight exchanges.

Was replaced by Donnacha O'Callaghan for the final quarter but still done enough to secure himself another Lions tour.

The tough Aussie-born Welshman has proved a revelation this season and turned in another outstanding performance when it mattered.

Tackled powerfully and made his presence felt throughout, matching up well to O'Connell.

The Ireland pack leader again failed to hit the heights of which he is capable, raining down blows on Sidoli as his frustration at events crept in.

Jones carried the ball well, despite conceding one penalty for holding on in the tackle, and is proving an effective addition to the Welsh pack.

Did much of the spade work in the back row effort, while Easterby struggled to match him.

Very much a Lions candidate at the start of the campaign, the Irishman has struggled to maintain his reputation and may now miss out on a place.

The stand-out Welsh forward of the campaign did not quite match his previous brilliance, but still supported the attacks well and did his fair share of tackling.

One glaring error when his knock-on spurned a huge overlap, but will be forgiven that aberration.

O'Connor is one of his main rivals for the Lions number seven jersey, but the Irish scavenger was unable to disrupt too much Welsh ball as his forward colleagues floundered.

Owen was again highly prominent with the ball in hand, showing his intelligence to find space and put his team-mates into it.

Natural leadership skills have been an extra bonus, and pulled the side together well when Ireland threatened in the closing stages.

Foley's failure to finish a try in the right corner with Shane Williams in front of him spelled the beginning of the end for Ireland's challenge, and he departed before the hour.