Joe Burgess pounced for two late tries to help secure Wigan’s first league win since April.
The Warriors were clinging onto a nervous 16-12 lead heading into the final 10 minutes.
But Burgess crossed twice in five minutes - in the 73rd and 78th minutes, both converted by George Williams - to give the final scoreline a flattering look.
Until then, and aside from a purple patch in the first-half, it had been a scrappy and largely unconvincing performance from the hosts.
But given they hadn’t secured a Super League win in eight matches, many would have taken this victory - any victory - before kick-off.
The two-points eased worries of being dragged into the bottom-four, and saw them leap Huddersfield into seventh in the table.
As well as his two late tries, Burgess also produced a stunning try-saving tackle on Stefan Marsh moments earlier when the outcome of the match was in the balance.
Back-rowers Liam Farrell and John Bateman also made telling contributions on an afternoon when many were below-their-best.
The fact this game took Wigan to the two-thirds mark of the season, and was being described as must-win, illustrated their recent misery in the league.
Eight games without a win was their worst run of form in more than a century and, more pertinently, had narrowed their hopes of reaching the top-four.
As expected, luckless prop Tony Clubb returned after a spell on the sidelines following surgery to remove a kidney.
Anthony Gelling was back at centre - allowing Burgess to return to his preferred position on the left-wing - and Liam Marshall’s 22 tries in 19 matches wasn’t enough to secure him a spot; Lewis Tierney replaced him on the right edge.
Widnes, without suspended Rangi Chase, had won three of their last four games and headed into the match knowing they had won twice at the DW Stadium last year.
With Ian Lenagan and rugby director Kris Radlinski absent, injured forward Joel Tomkins sat in the chairman’s seat - part of his training, perhaps, for a planned management role when he hangs up his boots.
At half-time, Tomkins could report to them that Wigan seemed on course for victory after establishing a 16-6 lead.
The early passages were scrappy and tepid, with several home chances breaking down and Widnes conceding three early penalties.
If the sloppy start was down to nervousness, Sean O’Loughlin helped ease those worries with a 17th minute opening try.
He coolly collected Thomas Leulaui’s angled kick, Williams tagging on the extra to make it 6-0.
Widnes had chances of their own, but the defensive line was well-marshalled and Sam Tomkins cleaned up well at the back.
Clubb came off the bench - to loud applause from the home faithful - and instantly made his presence felt with a strong, metre-eating charge. Moments later, he extended their lead when he thundered over under the sticks for a 32nd-minute try, Williams booting his 10th successive goal spanning three games.
A knock-on by Widnes prop Alex Gerrard - thought to be on Warriors’ radar for 2018 - presented them with a chance to cross again four minutes later. The ball was spread to the right, where Tierney jetted over to make it 16-0 and put the home side well in control.
But Widnes struck a foothold into the contest on the stroke of half-time. Joe Mellor stepped beyond Oliver Gildart to break and, from their next play, Lloyd White was able to ground a Corey Thompson kick over, which the former converted.
Aside from a Gildart break, the start of the second-half was a lifeless affair interrupted by frequent errors.
Wigan just couldn’t get any flow to their attacks - Williams enduring an off-day, and he certainly wasn’t alone - and their indiscipline only amplified their woes.
Widnes weren’t much better, but in the 56th minute, they capitalised from a fortuitous ricochet to cut their hosts’ lead to a fragile four-points. White again scored the try, and converted, after selling Tomkins an audacious dummy.
Wigan found themselves on the ropes, but O’Loughlin returned to steady the ship, and then a brilliant tackle by Burgess on Marsh saved a certain try.
Cheap penalties continued to piggyback Widnes into their half - Willie Isa and McIlorum chief culprits. But as the game entered the final 10 minutes, Farrell - celebrating his 27th birthday - stole the ball from Chris Bridge to set-up an unexpected attack. And a crisp, right-to-left shift involving O’Loughlin and Tomkins sent Burgess arcing over in the corner.
Williams booted the extras to open up a 10-point lead and, moments later, Burgess grounded Farrell’s kick. Williams again added the extras to secure a win which looked more comfortable than it felt.
The crowd of 12,758 included several hundred free tickets given to Widnes season ticket holders as a good-will gesture for the fixture switch in February.