World Rugby have told Wales that the television match official made a mistake with his controversial decision to disallow them a try in their Six Nations defeat by England last weekend.
With England leading 12-0 at Twickenham on Saturday, Wales back Gareth Anscombe, under pressure from home wing Anthony Watson, chased down a kick ahead from fly-half Rhys Patchell.
It was a close call but many observers felt Anscombe had been first to the ball and grounded it correctly.
Wales coach Warren Gatland, speaking after full-time, said televison match official Glenn Newman, his fellow New Zealander, had made a "terrible mistake".
Had the try been awarded England's advantage would have been cut to 12-5, with a conversion to come.
As it was, England held on for a 12-6 win with Wales restricted to two penalties.
But on Tuesday a spokesman for the global governing body said: "World Rugby has clarified to the Wales team management as part of the usual review process with teams that the TMO made an error in the application of law during the England versus Wales match at Twickenham.
"In accordance with law 21.1 b, Wales should have been awarded a try as the Wales player grounded the ball."
Gatland took up the issue with World Rugby's high performance match officials manager Alain Rolland, himself a former Test referee, and Wales assistant coach Rob Howley said Tuesday: "That phone call took place -- I think it was yesterday (Monday) -- and Alain Rolland confirmed on behalf of World Rugby the TMO made a mistake. It's happened.
"It is disappointing that happens in professional sport, but we focus on the next two weeks and getting ourselves ready for Ireland," the former Wales scrum-half added.
Howley insisted, however, that Wales could still have won the game regardless of Newman's ruling.
"There was plenty of time after that decision. We had a couple of opportunities which we should have taken."
Wales, who opened their Six Nations campaign with a 34-7 thrashing of Scotland, next play Ireland in Dublin on February 24.
- 'Compete with Ireland' -
Despite last weekend's loss, they remain in title contention behind Ireland and reigning champions England, the only two unbeaten teams left in this season's tournament.
And Wales could be strengthened for their Lansdowne Road meeting with Ireland next week by the return of several senior players.
Fullback Leigh Halfpenny, a late withdrawal from the England game, is recovering from a foot infection while Saracens wing Liam Williams played for the European club champions last weekend.
Fly-half Dan Biggar and No 8 Taulupe Faletau, both yet to feature in this season's Six Nations because of injuries, are also on the way back.
"At this moment, the redness of the foot and the infection is okay," Howley said, of Halfpenny. "He will take some part in rugby over the next couple of days.
"Taulupe is back to rugby this week. Dan Biggar is going through his return to contact, and hopefully will be doing some rugby by the end of the weekend."
Howley added: "We know we can compete with Ireland. Our recent results show that.
"A lot of our players are familiar with the Irish players, and we will go there with a great chance of putting them under pressure.
"I love going to Dublin, the players enjoy it and you are up against one of the best sides in the world.
"We've got three games left -- two at home (against Italy and France) -- and a huge challenge in Dublin. If you only lose one game, the past has shown you can still go on and win the championship."