The 34-year-old New Zealander, who is sticking by his decision to hang up his boots at the end of the season despite earning a place in the 2012 Dream Team, produced some devastating finishing to destroy a sorry-looking Catalan side whose suspect away form again let them down.
Carmont struck twice in the first eight minutes to give the Warriors a flying start and completed his hat-trick on 67 minutes, each time profiting from the sublime ball distribution of another departing overseas star, Brett Finch.
Wigan's comfortable victory earned them next week off and a passage straight through to a home semi-final, where they will face a much sterner test of their title credentials.
The Catalans' collapse rekindled memories of their 44-0 thrashing by Wigan in last season's play-offs and, although this time they live to fight another day, they will have to find some drastic improvement before playing a sudden-death tie in Perpignan next Saturday.
Wigan never looked back after scoring two tries in the first eight minutes. Stand-off Finch was the architect for man of the match Carmont on both occasions, with loose forward Liam Farrell supplying the final pass for his second try.
The Catalans struggled to find any cohesion throughout the first half and, after centre Vincent Duport had a try disallowed for a knock-on, they conceded again on 23 minutes when scrum-half Thomas Leuluai took Finch's pass and dummied his way past Gregory Mounis to touch down.
It took a solo effort from Dragons second rower Louis Anderson to breach the Wigan defence on 34 minutes but the Warriors struck again on the stroke of half-time through centre Darrell Goulding. Pat Richards kicked his third goal to make it 22-6 and it was a similar story in the second half as the Catalans struggled to make their mark.
Another superbly timed pass from Finch got Farrell through a gap in the visitors' defence within two minutes of the re-start and second rower Harrison Hansen was only prevented from scoring by an illegal ball steal by full-back Clint Greenshields.
Full-back Sam Tomkins out-jumped Setaimata Sa to touch down Matty Smith's high kick on 52 minutes. Carmont made the most of some shocking defence to complete his hat-trick before winger Josh Charnley, having switched to full-back with Tomkins taking a rest, brought the 7,232 crowd to its feet with a thrilling 90-metre try.
- Brett Finch