The Nigerian frontman scored the only goal of the match inside 15 minutes after latching onto John Lundstram's raking pass over the top. Dessers still had plenty of work to do, taking a superb touch to round hesitant Buddies keeper Zach Hemming before rolling the ball into an empty net.
St Mirren responded well to falling behind and created a number of half-chances before the interval, with on loan Celtic midfielder Kwon Hyeok-kyu at the heart of their positive attacking play. The South Korean squandered an opportunities from the edge of the box before testing Joe Hart with a rasping effort.
Gers manager Philippe Clement made two changes at half-time with Todd Cantwell and Scott Wright brought off for Tom Lawrence and Ross McCausland. The decision helped the visitors produce a more controlled second half performance but they were unable to add to their tally.
The lively Dessers was denied a second goal after hitting the right-hand post shortly after substitute Lawrence flashed a long-range strike narrowly wide of the target. Saints were thwarted a late equaliser when defender James Bolton's header struck the woodwork.
Here’s our post-match Rangers player ratings from the SMiSA Stadium:
Unused subs: Robby McCrorie (GK), Fabio Silva, Leon Balogun, Adam Devine.