With the visitors needing a victory from the first post-split fixture in the Scottish Premiership, an own goal from Saints centre-half James Bolton put the Light Blues ahead on 32 minutes but just five minutes later the game was level, with Mikael Mandron finding the net via the post with a well-taken header.
With the clock ticking down in the second half Rangers needed someone to step up and Dessers did just that with his 20th goal of the season, although the Nigerian international will be the first to thank James Tavernier for his wonderful cross.
St Mirren had an opportunity to test Jack Butland after just 45 seconds after the kick-off. A moment of hesitancy from Tavernier allowed Mandron to get a low shot away, with Rangers’ number one diving at full stretch to his right to make a good stop.
John Lundstram then looked to drive his team forward, the midfielder curling a teasing cross to the back post which was inches too high for Dessers before he tried his luck from 20 yards but his powerful effort went wide.
It was a lively and open start to the match and seven minutes in Butland had to be sharp to make another impressive save to deny Mandron who burst into the 18-yard box and went across the keeper with his left boot as he attempted to find the opposite bottom corner of the net.
It was end-to-end football in the opening period of the game, with Butland making another confident save from Conor McMenanin’s deflected shot from distance.
Fabio Silva, on the return to the Gers starting eleven, then got in behind the Saints backline and sprinted towards goal. The experienced Alexander Gogic, however, showed excellent recovery speed to make an important block.
Before the half-hour mark Stephen Robinson’s side enjoyed a positive passage of play which resulted in Mandron heading a deep cross back into the path of McMenanin but his header went over.
Rangers then got their noses in front on 32 minutes. After Borna Barisic took a short corner to Todd Cantwell, the Croatian launched a high, in-swinging cross to the back post which goalkeeper Zach Hemming nervously palmed away. It fell to Mohamed Diomande who, from a tight angle, cleverly headed the ball across the goal and into the danger area and James Bolton, under pressure from Dessers, put the ball into his own net.
Rangers’ lead only last for five minutes though, with Mandron getting his side back on level terms with a strong downward header from 10 yards which clipped the post on its way in.
It was a good finish from the number nine but Clement will have been frustrated at the space he managed to find in the penalty area.
Just before half-time Butland was called into action and he produced a moment of real quality. Once again a deep cross was headed back inside and when Bolton volleyed the ball goalwards the Gers goalkeeper somehow instinctively flicked the ball over the crossbar with his fingertips, leaving the St Mirren defender stunned that he hadn’t scored and put his team in front at the break.
With no substitutions by either manager for the restart, Clement waited until the 55th minute to make his first switch, with Ross McCausland replacing Silva on the left flank.
With an hour played, Rangers needed a spark in the final third of the pitch as both sides struggled to create any clear-cut chances in the second half.
On 63 minutes a rising volley from St Mirren captain Mark O’Hara had the home supporters out of their seats but was watched comfortably by Butland.
Todd Cantwell tried to inspire his side, the playmaker jinking into the box with a drop of the shoulder but he didn’t put quite enough curl on his shot as he attempted to find the inside of Hemmings’ far post.
On 74 minutes Rangers got the all-important goal they were waiting for and, not surprisingly, it was teed up by Tavernier.
The Gers skipper whipped in a delightful cross from the right which left Hemming in no man’s land and Dessers was there to head the ball into the net before celebrating with the bears behind the goal.
Substitute Tom Lawrence came close to grabbing a third goal for his side from a breakaway, the midfielder cutting inside a defender and beating Hemming but Gogic did incredibly well to get back and flick the ball away before it crossed the line.
ST MIRREN: Hemming, Bolton, Tanser, O’Hara, Mandron (Olusanya 70), McMenamin (Jamieson 74), Kiltie (Scott 74), Gogic, Boyd-Munce (Baccus 84), Fraser, Strain (Brown 84)
SUBS NOT USED: Urminsky, Taylor, Dunne
GOALS: Mandron 37
RANGERS: Butland, Tavernier, Lundstram, Souttar, Silva (McCausland 55), Dessers, Cantwell (Lawrence 75), Sterling, Balogun, Barisic (Wright 75), Diomande
SUBS NOT USED: McCrorie, Goldson, Dowell, Roofe, Davies, Raskin
GOALS: Bolton 32og, Dessers 74
REFEREE: Nick Walsh