Wales beat Italy in Six Nations opener

But they will meed a considerable improvement to threaten next Saturday's opponents England after Wales triumphed 33-7 following tries during the final quarter from centre Jonathan Davies, plus wings Liam Williams and George North as they posted 30 unanswered points in the second period.

Full-back Leigh Halfpenny kicked 18 points as Wales reeled off an 11th successive victory over the Azzurri, who struck first with an Edoardo Gori try that fly-half Carlo Canna converted.

But while the final scoreline was convincing, Wales trailed 7-3 at the break as Italy sensed another memorable day under new coaching chief Conor O'Shea less than three months after claiming an historic triumph against South Africa.

Ultimately, the home side were undone by a combination of poor technical discipline - they repeatedly fell on the wrong side of referee JP Doyle - and Wales belatedly finding some form as they made it four wins on the bounce under interim head coach Rob Howley.

Six Nations title holders England, though, will be an altogether tougher threat when Wales look to inflict a first defeat on their fiercest rivals during Australian Eddie Jones' coaching reign.

Forecast rain arrived an hour before the start in Rome, with Wales fielding 10 of the team that accounted for South Africa last time out, including a first Six Nations start for Gloucester back-row forward Ross Moriarty and scrum-half Rhys Webb making his Test match return following injury.

Italy, meanwhile, included 13 players from Zebre and Treviso as they looked to end a long run of defeats against Wales and claim just a 13th Six Nations victory in 86 starts.

Wales missed an early chance to go ahead when Halfpenny sent a long-range penalty wide, and there were a couple of immediate concerns for the visitors as North needed treatment on his right leg and skipper Alun Wyn Jones went off as a blood injury, with Cory Hill temporarily replacing him.

Wales dominated initial territory on a slippery surface, showing plenty of creative signs as flanker Justin Tipuric featured prominently and Liam Williams was only just clawed back by an Italian defender after catching fly-half Dan Biggar's kick at full speed.

Jones returned to action 11 minutes after going off, and Wales almost delivered a scoring breakthrough after Biggar's poor pass to centre Davies bounced off his foot, but Italy prop Andrea Lovotti managed to clutch possession before Davies could pounce.

And the Azzurri then enjoyed their best spell of a scrappy opening 25 minutes, winning Welsh scrum ball before skipper Sergio Parisse was only denied a try by three opposition players combining to stop him.

But Italy did not have to wait much longer, as more impressive close-range work from their forwards ended in Gori diving over for a try that Canna converted, making it 7-0 with 10 minutes of the first half left.

Halfpenny cut the deficit with an angled penalty just before the break, but it was largely a 40 minutes to forget for Wales, as one statistic - nine missed tackles - underpinned an unconvincing effort.

Biggar, who needed treatment after being on the receiving end of a crunching tackle, did not reappear for the second period and was replaced by Ospreys back Sam Davies, who gained his first taste of Six Nations action.

Davies, who impressed off the bench during the autumn Tests this season, had a golden opportunity to enhance his burgeoning reputation, and a second Halfpenny penalty immediately cut the deficit before he completed his hat-trick five minutes later.

Wales led for the first time, and a fourth Halfpenny strike made it 12-7 before Webb sparked a brilliant attack with a one-handed pass and was then just inches short of a try after the visiting forwards quickly recycled possession.

Wales now had a stranglehold on the contest - underlined when Lovotti was sin-binned following repeated team scrummaging infringements - and the visitors capitalised immediately as smart work from Sam Davies and Scott Williams enabled Jonathan Davies to dive over.

Halfpenny's conversion took Wales 12 points clear, effectively ending hopes of a famous Italy win, before Liam Williams finished the Azzurri off.

North then struck with a brilliant late breakaway score and the visitors could relax, even if they failed to secure a try-scoring bonus point that many might have expected.