The 27-year-old Kiwi was in sparkling form for Trinity as he showed tremendous pace to score two tries and created two others for winger Mason Caton-Brown and was a constant thorn in the Vikings defence.
As well as Tupou and Caton-Brown scores, Wakefield claimed other tries through Sam Williams and Tinirau Arona with Liam Finn landing six goals to secure a convincing win.
The defeat for Widnes means they will finish in the bottom two and will face four games away and three at home as they fight for their Super League lives in the Middle 8s.
Widnes’s points came from a solitary try by Joe Mellor and two goals from Stefan Marsh which took him past the 250-point mark in his Super League career.
Widnes made the perfect start and were ahead after just six minutes when Mellor scored a fine solo try as he dummied his way through the Trinity defence from 20 metres out. Marsh converted but that was as good as it got for Denis Betts’s side.
Caton-Brown dived over, Finn missed the conversion but added a penalty to level matters at 6-6.
Widnes – down to 12 after Ryan Ince was sin-binned – edged in front with a Marsh penalty, before Tupou and Williams crossed to give Wakefield an 18-8 interval lead.
Second-half tries from Arona, Caton-Brown and Tupou secured the points for Trinity.
Widnes: Thompson, Ince, Bridge, Runciman, Marsh, Mellor, Chase, Dudson, Heremaia, Buchanan, Houston, Whitley, Cahill. Substitutes: Manuokafoa, O’Carroll, Johnstone, Olbison.
Wakefield Trinity: Grix, Jones-Bishop, Arundel, B. Tupou, Caton-Brown, Williams, Finn, Walker, Wood, Huby, Ashurst, Hadley, Arona. Substitutes: Annakin, Hirst, Fifita, England.
Referee: C Kendall (RFL).