Ireland's first try came in the fifth minute after a sustained bout of pressure with O'Connell, appearing in the centre, bursting over on the right at for the opening score of the afternoon.
Wales responded with a well worked try five minutes later with their skipper left wing Gareth Thomas touching down in the right hand corner. Ireland response was immediate and after Humphreys had kicked a penalty to touch metres from the Welsh line Keith Wood smashed his way over from the resultant ruck but was penalised for a double movement.
Ireland continued to apply the pressure up front and used their lineout dominance to build the phases. Denied on a few occasions, they finally scored their second try when they flashed a ball wide to Alan Quinlan in midfield who crashed over under the posts. Quinlan suffered a cut in the process and was replaced temporarily by David Wallace.
Wales were reduced to 14 just before half time when Iestyn Harris was yellow carded for a high tackle on Anthony Horgan.
Wallace replaced Anthony Foley at the start of the second half and made an immediate impact starting a move with a 30 metre break that ended with him scoring to the right of the posts having taken an inside pass from Horgan.
Five minutes later try number four arrived from Malcolm O'Kelly after Geordan Murphy had broken clear from half way and then Kevin Maggs carved out a great opening only for Reggie Corrigan to knock on with the line in sight.
Humphreys retired with a knee injury in the 60th minute, replaced by Girvan Dempsey who went to full-back with Murphy switching to out-half.
The Welsh hit back with a try from Garan Evans but Ireland and O'Connell had the final say with that late try.
Ireland G Murphy; T Howe (G D'Arcy 76 min), B O'Driscoll, K Maggs, A Horgan; D Humphreys (G Dempsey 60 min), P Stringer (G Easterby 76 min); R Corrigan, K wood (S Byrne 67 min), S Best (J Fitzpatrick 60 min); M O'Kelly (D O'Callaghan 67 min), P O'Connell; A Quinlan, K Gleeson, A Foley (D Wallace ht).
Wales. N Robinson; G Evans, J Robinson, I Harris, G Thomas capt; C Sweeney, D peel; D Jones, M Davies, B Evans (G Jenkins 51 min); M Owen (V Cooper 65 min), G Llewellyn; R Oakley, R Parks, A Popham.
Referee: Joel Dume (Fra).