Jason Puncheon hit a decent long-range effort which looked to have beaten Chairboys goalkeeper Scott Shearer but it slid just wide of the upright.
Shortly afterwards, a Puncheon corner found Jabo Ibehre just a couple of yards from goal but the striker’s header brought a superb save from Shearer.
Moments before the break Doumbe pushed forward from the right and cut inside to shoot powerfully across goal and into the bottom corner.
Peter Taylor made three changes at half-time but the Dons continued to dominate and came close to a second when Lewis Gobern tested Shearer with a fierce strike from distance.
Wycombe struggled to retain possession throughout but came close to an unlikely late equaliser when Stuart Green had the goal at his mercy but Willy Gueret saved with an outstretched leg.