Warren Gatland's return was spoiled by Ireland as the world's number one side humbled Wales in the opening Six Nations match in Cardiff.

Wales improved in the second half and responded with a Liam Williams try.

But it was Ireland who completed the scoring with a bonus-point try for flanker Josh van der Flier.

That put the gloss on Ireland's first Six Nations victory in Cardiff for 10 years as Andy Farrell's side took another step in the right direction as they target Six Nations and World Cup success in 2023.

Gatland, who was brought back as Wales coach to replace fellow New Zealander Wayne Pivac, will now know the size of his task in a World Cup year.

Ireland overpowered a woeful Wales side in the first half, with the hosts repeatedly punished for ill-discipline and inaccuracy.

The second half saw Wales dominate possession and territory but Ireland were content to absorb the pressure as they continually turned over their opponents.

The fourth and final try demonstrated Ireland's clinical edge as they recorded their biggest Six Nations win in Cardiff since 2001.

Ireland number eight Doris was outstanding, while player-of-the-match Hugo Keenan excelled from full-back.

Wales' troubled build-up

The build-up for Wales was dominated by allegations of sexism and misogyny within the Welsh Rugby Union, which resulted in chief executive Steve Phillips resigning.

Bosses were hauled before the Senedd and a taskforce created to look at the culture of the organisation.

The Tom Jones anthem Delilah was not included on the choir's playlist at the Principality Stadium because the lyrics have been linked to domestic violence, although renditions were sung by some in the Cardiff crowd.

The off-the-field controversy overshadowed Gatland's return for his second spell as Wales head coach. During his first stint between 2008 and 2019, Wales secured four Six Nations titles and three Grand Slams.

He was back for more following a miserable 12 months when Wales won three Tests in 12 games and suffered humiliating home defeats against Italy and Georgia.

Gatland had kept faith with 12 of the starting side from Pivac's last game, with the team picked boasting more than 900 caps between them and eight players aged over 30.

On this evidence, Wales might have to reconsider this strategy in the coming weeks.

Hooker Ken Owens, 36, became Wales' oldest captain as he led his nation for the first time.

Ireland arrived as the world's top team, a status they achieved following two away victories over New Zealand and consolidated with autumn wins against South Africa and Australia.

Lions prop Tadhg Furlong was ruled out through injury and replaced by Finlay Bealham, with Sexton, 37, starting and World Rugby men's player of the year Josh van der Flier at flanker.

There was a late change with scrum-half Jamison Gibson-Park ruled out with a hamstring injury with Lions number nine Conor Murray starting.

Gibson-Park's absence was expected to result in a change of tempo for the visitors but it made no difference.

Ireland's stunning start

Ireland started strongly, with a clever Lowe kick setting up the attacking platform for the opening try.

Patient build-up eventually yielded an opportunity for Doris to dive over with Sexton converting.

Ireland's power came to the fore again as Wales' indiscipline told, with Ryan diving over from a short tap penalty as Andy Farrell's side led 14-0 inside 10 minutes.

Wales bounced back with Rio Dyer almost scoring with a loose kick ahead but he was denied by Keenan before Biggar slotted over the hosts' opening points.

Sexton responded with his own penalty before Lowe intercepted Biggar's pass to sprint 70 metres to score. Sexton converted and slotted over another penalty.

Wales centre Joe Hawkins, on his Six Nations debut, made an incisive break but Biggar could not capitalise as he was turned over just short of Ireland's line.

The home side were also denied when Jac Morgan was held up by Andrew Porter with Ireland holding a 24-point lead at half-time, an advantage that did not flatter them.

Wales improve as Ireland absorb pressure

The home side's inaccuracy in the opening 40 minutes was in contrast to their clinical opponents, but they initially solved that at the beginning of the second half.

An inventive lineout was taken by North before paving the way for a clever Hawkins pass which allowed Liam Williams to canter over for a converted try.

Ireland's ill-discipline gave Wales a restart penalty but the momentum was initially halted with a wayward lineout throw and a scrum penalty conceded by replacement Dillon Lewis, who had replaced Tomas Francis.

Full-back Williams, a late call-up to start for the injured Leigh Halfpenny, continued his impressive performance with a scything break before being the victim of a late challenge from replacement Iain Henderson.

The hosts enjoyed possession and territory dominance but wasteful Wales struggled to turn this pressure into points as Ireland absorbed and repeatedly repelled the attacks.

A raft of replacements included Wales hooker Scott Baldwin making his first international appearance in almost six years.

Full-back Williams was shown a yellow card by English referee Karl Dickson for a high tackle on Sexton with his shoulder.

Wales continued to attack but could not cross for a second score and Ireland demonstrated their clinical edge with Van der Flier diving over for the final score.

Wales face a trip to Scotland next weekend, with Ireland hosting France in what could prove a pivotal game in the battle for the 2023 Six Nations trophy.

Line-ups

Wales: L Williams; Adams, North, Hawkins, Dyer; Biggar, T Williams; G Thomas, Owens (capt), Francis, Beard, AW Jones, Morgan, Tipuric, Faletau.

Replacements: Baldwin, Carre, Lewis, Jenkins, Reffell, Webb, O Williams, Cuthbert.

Ireland: Keenan; Hansen, Ringrose, McCloskey, Lowe; Sexton (capt), Murray; Porter, Sheehan, Bealham, Beirne, Ryan, O'Mahony, Van der Flier, Doris

Replacements: Herring, Healy, O'Toole, Henderson, Conan, Casey, R Byrne, Aki.

Referee: Karl Dickson (ENG)

Touch judges: Angus Gardner (AUS) & Luke Pearce (ENG)

TMO: Tom Foley (ENG).