Samoa sent Six Nations holders Wales crashing to their fifth consecutive loss after the visitors secured a 26-19 win at the Millennium Stadium on Friday.
It was the hosts' fourth negative to the islanders and followed Rob Howley's charges' defeat to Argentina at the same venue only one week ago.
Suddenly a November whitewash seems likely, with Wales now preparing to face New Zealand and Australia in their final Test series fixtures.
The visitors came out of the blocks firing as they looked to kick on from their impressive win over Canada in Colwyn Bay a week ago. And they managed to cross the whitewash within two minutes against the sterner opposition when number eight Taiasina Tuifua broke through a somewhat non-existent defence before recycled ball was moved wide to Paul Williams and then George Pisi, with the Northampton Saints centre sending over Faatoina Autagavaia on the right.
The impressive Tusi Pisi's conversion made it 0-7 with the match still very much in its infancy. For Welsh supporters, it was a moment of realisation, realisation that their Grand Slam champions were in for a big test of their credentials.
Leigh Halfpenny, who was on-form with the boot in Cardiff, pulled the hosts back to 3-7 with 16 minutes played after a ruck infringement and then cut matters down to a point on the half-hour. By this point Wales had been forced to make a change, as Richard Hibbard was hurt.
Despite their six points, Wales were not having things their own way but were the recipients of a gift from Pisi, with the fly-half throwing a suicide pass that Ashley Beck gobbled up and then set off for a 70 metre sprint to the whitewash. Halfpenny made it 13-7 with the extras.
The assured Pisi did reduce the arrears off the kicking tee with the last play of the first-half, which made the contest beautifully balanced at 13-10 with 40 minutes remaining in Cardiff.
After the turnaround the match continued to excite and when Kahn Fotuali'i scooted down the blindside at a ruck close to halfway to set up centre Pisi for a superb finish in the corner, the Samoans were ahead again. Fly-half Tusi could not add the extras however, and one wondered whether that missed conversion on 47 minutes would come back to hurt them.
An exchange of penalties from Halfpenny and Pisi then troubled the scorers as the lead changed hands five times during the second-half. Up 21-19, Samoa repelled a rare attack by Wales soon after, with the hosts struggling to make any real headway with ball in hand.
Instead it was Samoa who had the final say when David Lemi kicked ahead, Halfpenny and Autagavaia both missed the bouncing ball to hand replacement Johnny Leota a try late on.
Man of the match: A toss-up between the half-backs in blue. Let's go for Tusi Pisi's effort.
Moment of the match: The finish from George Pisi was something special. It had to be him.
Villain of the match: Maybe of a couple of let's say 'choice' tackles could make it in there but there was nothing major to write home about. Next up for the Welsh will be New Zealand.
Pen: Halfpenny 4
Tries: Autagavaia, G Pisi, Leota
Con: T Pisi
Pen: T Pisi 3
Wales: 15 Leigh Halfpenny, 14 Alex Cuthbert, 13 Ashley Beck, 12 Jamie Roberts, 11 George North, 10 Dan Biggar, 9 Mike Phillips, 8 Toby Faletau, 7 Justin Tipuric, 6 Ryan Jones (capt), 5 Ian Evans, 4 Bradley Davies, 3 Aaron Jarvis, 2 Richard Hibbard, 1 Paul James.
Replacements: 16 Ken Owens, 17 Gethin Jenkins, 18 Scott Andrews, 19 Luke Charteris, 20 Sam Warburton, 21 Tavis Knoyle, 22 Rhys Priestland, 23 Scott Williams.
Samoa: 15 Faatoina Autagavaia, 14 Paul Perez, 13 George Pisi, 12 Paul Williams, 11 David Lemi (capt), 10 Tusi Pisi, 9 Kahn Fotuali'i, 8 Taiasina Tuifua, 7 Maurie Fa'asavalu, 6 Ofisa Treviranus, 5 Filo Paulo, 4 Daniel Leo, 3 Census Johnston, 2 Ole Avei, 1 Sakaria Taulafo.
Replacements: 16 Ti'i Paulo, 17 Villiamu Afatia, 18 James Johnston, 19 tbc, 20 Tivaini Fomai, 21 Jeremy Su'a, 22 Johnny Leota, 23 Robert Lilomaiava.
Referee: Pascal Gauzere (France)
Assistant referees: Wayne Barnes (England), JÃ©rÃ´me Garces (France)
Television match official: Giulio De Santis (Italy)
By Adam Kyriacou