The physical South Sea Islanders denied Wales possession and took their chances to advance further in the main competition while the Dragons were left to face Fiji in the Plate semi-final.
Fiji, currently the main challengers to high flying New Zealand who are leading the series after two completed rounds, proved no match for a resurgent Wales who ran away with a comfortable 27-5 triumph where Rhys Jones emulated skipper Rhys Shellard's exploits of yesterday when he raced over for a hat-trick to put Wales in control.
Wales attacking play was exemplary with Jones's tracking and support play a standout feature while Shellard was again in inspirational form, cajoling and encouraging his young side towards a shock victory.
In the Plate semi final Jones scored 17 points through his three tries and a conversion, as the Dragons beat the champions from the Gold Coast, Fiji. Debutant Alex Webber and Will Thomas also scored for the victors to send Wales through to the final against Canada.
James Davies, younger brother of Johnathan Davies who was playing at the Millennium Stadium at the same time against Australia, used his power and pace to cross the whitewash after only 24 seconds to send Wales on their merry way. Jones also touched down and converted all three tries to secure Wales a hard fought 21-14 victory.
A delighted skipper, Rhys Shellard, said: "I'm very proud of the boys. We let ourselves down against Samoa in the quarter-final. We didn't come out firing but we put things right after that to win the Plate final.
"The win should give us a bag load of confidence going into next week's round in South Africa. We've got some good youngsters coming through and we'll definitively have the aim of hitting the ground running next week in Port Elizabeth."
The success saw Wales pick up 13 points from the tournament to take their series tally to 18 after two rounds with New Zealand leading the way with 38.