Cardiff - Jamie Roberts propelled Wales to a frustrating 24-3 Six Nations victory over Italy on Saturday to keep their hopes of a third Grand Slam in eight years alive.
Following three Championship triumphs Wales were overwhelming favourites to cruise past winless Italy at the Millennium Stadium.
But dogged Italy made life difficult for the hosts despite their abundance of brute force and finesse.
Warren Gatland's men led by just six-points at the interval thanks to a hat-trick of penalties from Leigh Halfpenny despite dominating both territory and possession.
But Roberts raced clear for a break-away try after 49 minutes to put Wales in a commanding position.
Italy continued to disturb Wales but man of the match Alex Cuthbert scorched clear at the death to put the result beyond doubt.
The Welsh can now look forward to a Grand Slam showdown with World Cup heartbreakers France in a week's time.
"We knew it was going to be tough from the start," said Cuthbert.
"We just tried to do our things and go for it - it was hard to break them down - they have a good defence and it was hard work.
"We take each game at a time and hopefully we will get a big crowd out next Saturday (against France)
Gatland was critical of Irish referee George Clancy calling him "over pedantic."
"But the boys tried really hard and at the end of the day we are four out of four.
"We are happy with the intent that was out there - but the boys are a little bit frustrated."
Wales were without Sam Warburton, after their inspirational skipper failed to recover from the Championship-threatening knee injury he suffered against England, with Ospreys youngster Justin Tipuric starting in his place.
But they welcomed back former captain Matthew Rees, who reformed the Dragons' all-Lions front-row for the first time since November 2010.
Luke Charteris also made his long-awaited international comeback off the replacement bench following the wrist injury he suffered at the World Cup.
Wales' giant backline made a rampaging start to the encounter with George North breaking three tackles with his first carry and Alex Cuthbert also making major inroads.
Leigh Halfpenny opened the hosts' account with a long-range penalty on nine minutes after Sergio Parisse was penalised.
But Faletau knocked on from the kick-off and Wales' reunited all-Lions front-row were pinned at the ensuing scrum to allow Bergamasco to level the scores.
Following an intense period of pressure, with Cuthbert running riot out wide, Halfpenny eased Wales back in front.
They continued to dominate affairs and pounded Italy with relentless waves of attacks. But they were let down by errors in the face of the visitors' committed defence in the final quarter.
Jamie Roberts came closest to breaking the deadlock after latching on to a Faletau offload. But the burly centre was hauled down short by Luke McLean and Alberto Scarbi.
Wales settled for Halfpenny's third penalty after Bergamasco was harshly penalised at the breakdown. Italy responded with a late rally but Wales held strong to enter the interval leading 9-3.
Wales were frustrated by Italy following the restart of play but Roberts struck with a long-range effort to settle the hosts' nerves.
Alun Wyn Jones pounced on loose ball inside the Welsh half and the ball was spread through Mike Phillips, Halfpenny and Priestland's hands for Roberts to slice through the Azzurri defence.
Halfpenny slotted the extras to hand Wales a 16-3 lead. They continued to cause Italy problems in attack but were dealt a major blow when the fullback was cruelly shown yellow after colliding with Parisse - despite competing for the ball.
Mass substitutions disrupted the flow of the game in the final quarter but Wales hung-on despite their numerical disadvantage.
With Halfpenny in the bin, Priestland stretched the lead further on 69 minutes and Cuthbert rounded off the victory with minutes to spare.
Captain Jenkins took a quick-tap and released Cuthbert, who went outside Fabio Staibano and raced clear before squeezing into the corner.