Saturday's match had been billed by the West Ham board as the "save our season game", although manager Avram Grant maintained that was more aimed at supporters to get behind the team than a shot across his bows.
Nevertheless, there was more than a sense of relief around the Boleyn Ground at the final whistle, with the Irons securing a first win since the end of September following goals from Valon Behrami, Victor Obinna and Scott Parker.
However, the Irons - now within three points of safety, but still bottom after Wolves' late winner against Sunderland - had keeper Robert Green to thank for saving a penalty from substitute Mauro Boselli just after the hour which could have set up a nervous finish, although Tom Cleverley netted a consolation on 85 minutes.
Grant had relegated Carlton Cole to the bench after the England striker had labelled last week's 3-0 defeat at Liverpool as "diabolical", while Wigan were without suspended duo Hugo Rodallega and Antolin Alcaraz following their red cards against Manchester United.
It was a positive start by the Hammers, as Frederic Piquionne looked lively at the head of the attack.
However, Wigan came into the game and winger Mohamed Diame dashed to the far touchline. He pulled the ball, which looked to have gone out of play, back for on-loan United youngster Cleverley to test Green with a low effort from 20 yards.
The home side were under pressure again when a low cross from Ronnie Stam had to be hacked clear in the six-yard box by James Tomkins.
There was more than a sense of frustration beginning to grow inside Upton Park as the half-hour mark passed and the Irons again were unable to make any real progress in the final third.
The Boleyn Ground, however, erupted in relief on 34 minutes when Behrami bundled in a knockdown from Piquionne after Lars Jacobsen's high ball into the Wigan box.
Junior Stanislas, back in the side after a groin injury, sent a snap-shot goalwards from 20 yards and Ali Al Habsi had to be alert to tip the ball over.
From the corner, the Wigan keeper then produced a brilliant reaction save to parry away Piquionne's bullet header.
West Ham should have been 2-0 up at the start of the second half when Piquionne found himself unmarked on the penalty spot but dragged the ball wide.
After both Pablo Barrera and Obinna dragged shots wide, the Hammers had a two-goal cushion on 56 minutes.
Piquionne carried the ball into the left side of the Wigan penalty area before cutting it back to Obinna. The on-loan Inter Milan forward promptly drilled a low strike into the bottom corner for his first Premier League goal.
Wigan responded by making a double change as Franco Di Santo and Jordi Gomez were replaced by Boselli and Victor Moses after 61 minutes.
The visitors then were awarded a penalty when Danny Gabbidon tripped Cleverley. Boselli stepped up to take the spot-kick with what was his first touch - but Green guessed right to make a fine save.
West Ham broke and felt they should have been given a penalty when Gohouri looked to have tripped Piquionne, but this time referee Mark Halsey waved play on.
Despite their lead, West Ham continued to look less than comfortable.
However, the points were secured with 15 minutes left when Obinna broke down the left and Parker arrived in the six-yard box to crash the ball past Al Habsi.
Piquionne was replaced by Cole for the closing stages, while Parker was given a standing ovation when he went off with seven minutes left.
Cleverley netted a consolation with a dipping drive on 86 minutes.
In stoppage time, Behrami fell to the ground after slipping and looked to have injured his groin and Wigan had a close-range effort from Gohouri ruled out for offside as finally it was West Ham's day.