An eighth successive win by the reigning champions set up a derby showdown with a rested St Helens - the last team to beat them - at the Totally Wicked Stadium next Friday for a place in the Grand Final.
The loser will have a second bite of the cherry, as do Salford, who will seek to keep alive their bid for a maiden Grand Final appearance when they play Castleford at the AJ Bell Stadium next Thursday.
The defeat brought Salford's eight-match winning run to an end despite the best efforts of half-back Jackson Hastings, the Man of Steel favourite who showed the Wigan fans what they can expect when he joins the Warriors next season.
The Red Devils' front row of former Wigan players led the way in an arm wrestle throughout a scoreless opening quarter as the teams tested each other out.
The breakthrough from England centre Oliver Gildart, scoring for the third successive match after taking stand-off George Williams' pass and hoodwinking his opposite number Kris Welham.
Zak Hardaker, who had earlier missed a penalty from in front of the posts, kicked the touchline conversion to make it 6-0 and Wigan thought they had scored again when right centre Chris Hankinson went through a gap only to be brought back for obstruction.
The visitors were rocking at that stage but they hung in and drew level just before the interval.
Replacement hooker Joey Lussick was denied a try when his opposite number Sam Powell got his body under the ball but there was no stopping second rower George Griffin two tackles later as Salford maintained the pressure.
Krisnan Inu's conversion made it 6-6, which meant the visitors were the happier side at half-time.
Wigan coach Adrian Lam's response was to bring on exciting Australian utility back Bevan French for the second half, with Williams switching to hooker in place of Powell, but with only limited effect.
Salford created the first scoring opportunity of the second half, full-back Niall Evalds working winger Ken Sio over at the corner, but slow-motion replays showed he had a foot in touch and Wigan took full advantage of the let-off with two tries in four minutes.
The first was gift-wrapped for scrum-half Thomas Leulua after Inu's careless offload near his own line put Jake Bibby in trouble and the second was the result of a break from inside his own half by winger Joe Burgess which was finished off by Williams.
Hardaker added both conversions to open up a 12-point lead but Hastings kept his side in the hunt by brushing off the challenge of forward Liam Farrell to score an opportunist try on 61 minutes.
Wigan had a chance to wrap it up but substitute forward Joe Greenwood dropped Sean O'Loughlin's pass on the line and they were forced to withstand a tremendous late onslaught from the visitors before they were able to celebrate.
