Wales survived a punishing physical examination by Samoa at the Millennium Stadium - but was made to sweat for a 17-13 victory.
Wing Leigh Halfpenny's early try, Wales' first in Cardiff since February, threatened a runaway home win.
It did not materialise though, as Wales needed three Dan Biggar penalty goals and a long-range Halfpenny strike to keep the determined South Sea Islanders at bay.
Samoa, four places below Wales in the International Rugby Board world rankings, had previously beaten its host three times from six attempts, including twice in the Welsh capital.
London Irish centre Seilala Mapusua's second-half interception try, plus two penalty goals and a conversion from first five-eighths Fa'atonu Fili, threatened another colossal upset.
It should have been even closer but centre Gavin Williams missed a late penalty chance from in front of the posts and then Samoa wasted a prime attacking opportunity, allowing Wales to breathe a huge sigh of relief.
Having lost to New Zealand last Saturday, Wales boss Warren Gatland wanted a result and performance to make people sit up and take notice.
But a crowd of just under 59,000 almost witnessed a Wales defeat.
Halfpenny shone throughout and there were some impressive moments from 21-year-old Cardiff Blues flanker Sam Warburton, yet Wales often played too deeply and were guilty of some desperately poor handling.
Samoa only came together as a squad last weekend but finished agonisingly close to claiming one of its most famous victories.
Samoa made its intentions clear from kick-off when No.8 Henry Tuilagi launched a bulldozing run into the Wales half, then fullback Lolo Lui flattened halfback Dwayne Peel.
Peel had sniped clear and freed Warburton, but Lui's questionable challenge left the Sale half-back requiring treatment before he could continue.
Biggar and his opposite number Fili exchanged penalties before the impressive Biggar created a high-class Welsh try.
His superb cross-kick was caught at full tilt by Halfpenny, who shrugged off opposite number David Lemi's challenge to touch down wide out. Biggar could not convert but Wales were up and running and 8-3 ahead inside seven minutes.
Biggar's second penalty, awarded after Mapusua was punished for not releasing possession in the shadow of his own posts, gave Wales further breathing space.
And with the home side dominating possession and territory, Samoa had its work cut out despite the best defensive efforts of Tuilagi and skipper George Stowers.
Wales, which is in the same 2011 World Cup pool as Samoa, continued to press, with Halfpenny and Warburton enjoying the team's expansive approach.
But the visitors worked their way back into kicking range to allow Fili two penalty opportunities in quick succession, the second of which he landed.
A raking touchfinder by fullback James Hook then took Wales deep inside Samoa's 22, but they could make no further headway and trooped off at half-time five points in front.
The Wales scrum had encountered its share of first-half difficulties, with former Saracens prop Census Johnston making considerable headway opposite Lions loosehead Gethin Jenkins.
So it came as some relief for Wales when Halfpenny rifled over a penalty from the halfway line that restored an eight-point advantage.
The Samoan pack, inspired by its front-row's efforts, raised the tempo and Wales found itself being dragged into a physical tussle it did not want.
Centre Tom Shanklin went off in the 48th-minute nursing a facial injury, which meant a third cap for Scarlets back Jonathan Davies, and Biggar's third