Responding to a limp defeat at lowly Castleford Tigers last time out, Warrington showed aggression and energy from the get-go, pinning their hosts deep inside their own territory for much of the opening quarter.
Yet despite their dominant play, steadfast Leigh defence limited them to just two points – Sneyd chipping over a penalty for Joe Ofahengaue’s high tackle on Sam Powell, who had been held up on the line moments earlier.
And having barely set an attacking boot in Wire territory, Leigh were soon level through O’Brien’s penalty for late contact by Wire debutant Ryan Matterson.
Yet order was restored in the 32nd minute when Josh Thewlis, inside his own half on the right wing, cut back into the centre with a breathless run, slaloming through challenges before sending Dufty in under the posts.
If there was hope for a below-par Leigh, and concern for Wire, it was that just one score separated the sides going into the second half.
Sneyd slotted a second penalty before George Williams’ superb kick down the left wing bounced kindly for Jake Thewlis to collect and cross for his eighth Super League try of the season.
Leading 14-2 with 15 minutes left, Dufty had a second score – and a potential decider – overturned by the video referee following a Lachlan Fitzgibbon obstruction.
And two minutes later, and having barely troubled the Warrington line, Leigh were back in it when Hanley stretched out to touch down O’Brien’s deflected grubber kick.
O’Brien’s conversion brought the Leopards back within six points, but Sneyd’s dead-eye penalty from long distance again took the visitors two scores clear.
But once again after a Warrington score was ruled out after a video review – this time from Toby King – Hanley powered through for a second try and O’Brien’s conversion cut the gap to 16-14.
Wire were suddenly hanging on and buckled moments later as Trout capped his 100th Super League appearance with the winning score from close range.