Named in coach Matt Peet's 21-man final squad six weeks earlier than expected after sustaining the injury in March, French needed less than three minutes after being introduced on the hour mark to skip over for his side's sixth try.
That 30-year-old French had been afforded the luxury of a cameo role was due in large part to the performance of his understudy, Jack Farrimond, who helped himself to Wigan's first two tries and orchestrated an emphatic start from which Rovers never recovered.
It added up to the biggest winning margin in a final since the Robins were hammered 50-0 by Leeds in 2015, and vindicated Peet's decision to name a team stacked with debutants for their 62-4 Super League loss at Craven Park just 10 days previously.
Questions over French's potential involvement had gripped the build-up to the tie, and the sight of the former Parramatta Eels star going through the motions in the warm-up suggested his name on the team sheet was little more than a diversionary tactic.
Either way, it enabled Farrimond to grasp centre stage. He made all the difference in an attritional first period in which Wigan were excellent defensively and Rovers somewhat inhibited, as if lacking the spark that drove them to end 40 years of trophy-less hurt at the same venue 12 months ago.
It added up to a nightmare start for Rovers, who lost prop Dean Hadley to a game-ending head injury with just three minutes on the clock, and two minutes later Wigan were in front when Farrimond threw a dummy and darted through to put his side four points to the good.
Jake Wardle was not far off a second and when Harry Smith escaped punishment after catching Robins winger Tom Davies high with 12 minutes gone, Willie Peters' men could have been forgiven for thinking it was not going to be their day.
They rallied with a tough repeat set just before the half-hour mark, pummelling the Wigan rearguard through consecutive sets, before Tyrone May almost broke through after a Farrimond kick was charged down.
Farrimond produced another moment of magic five minutes from the break when he streaked up-field off Oliver Partington's short pass, stepped in between two flat-footed Rovers defenders and scored under the posts, before Adam Keighran duly kicked his side into double figures.
With playmaker Mikey Lewis limping badly, Rovers were reeling, but they snatched at an unlikely chance seconds before the hooter when May's kick was grasped high by Peta Hiku, who raced clear and rolled over the line under pressure from Wardle.
If it gave the holders hope, it only served to make what unfurled in the second half more painful. Junior Nsemba dropped on to Smith's high kick to restore Wigan's double-figure advantage within three minutes of the restart, and Keighran kicked them 16-4 in front.
With Wigan threatening to score at will, Keighran helped himself to back-to-back tries to add to his six successful conversions that ultimately added up to a final record-equalling individual 20-point haul.
French duly arrived to add the gloss, and despite a second Hiku try nudging Rovers towards double figures, Luke Thompson duly completed the demolition with Wigan's seventh try of the afternoon before Sam Walters was red-carded with two minutes left for a dangerous tip-tackle on Bill Leyland.
