Six-time Super League winners were finally relegated with their 52-26 defeat to Huddersfield Giants last weekend.
However, the Yorkshire side produced a stunning 16-8 triumph at the Odsal Stadium on Sunday to hand James Lowes his first victory as head coach.
There was no sign of the surprise result when Dom Manfredi put Wigan ahead in the ninth minute, but scores from Danny Williams and Joe Arundel put the hosts 12-4 ahead at the break.
Matty Blythe further extended Bradford's lead and, though Manfredi's second try in the 68th minute sparked fears of a Wigan revival, Lowes' side held on for a fifth win of the campaign and avenged the 84-6 demolition in the reverse fixture back in April.
Also on Sunday, Chris Riley scored a hat-trick as Wakefield Wildcats boosted their play-off ambitions as they ran out 40-26 winners at Warrington Wolves, who lost for the second week running, while Huddersfield Giants triumphed 38-16 at home to Catalan Dragons.
Widnes Vikings were dealt a blow in their bid to reach the end-of-season play-offs after suffering a 44-22 defeat at table-toppers St Helens on Friday.
Tom Makinson was the star of the show at Langtree Park with a hat-trick, while Mose Masoe helped himself to two of the home side's tries.
However, neither Salford Red Devils nor Hull FC could take advantage of Widnes' loss.
Salford were locked at 12-12 at half-time with high-flyers Leeds Rhinos - playing without suspended captain Kevin Sinfield - on Friday.
However, two tries in the space of six second-half minutes from Carl Ablett and Stevie Ward put the visitors in control and, though Jordan Waine responded, Leeds held on for a 22-18 win.
Hull FC, meanwhile, were left ruing a flurry of three tries in the last 13 minutes from Castleford Tigers who battled back to draw 18-18 at the KC Stadium on Thursday.
Elsewhere, already relegated London Broncos made it 22 defeats from 22 outings this season as Hull Kingston Rovers ran in 11 tries in a 62-10 triumph in Friday's clash at The Hive.