Two goals from defender Mike Williamson proved to be enough to beat John Still's in-form Daggers team.
Both sides started brightly but the game was blown open when Wycombe striker Simon Church received his marching orders on 22 minutes.
Referee Pat Miller showed no hesitation in flashing the red card when Church lunged in two-footed on Dagenham midfielder Peter Gain.
But the visitors failed to capitalise on their advantage and looked desperate for ideas. They soon found themselves behind on 34 minutes when Williamson headed in Lewwis Spence's corner.
Still was furious with the tameness of the goal but the Dagenham boss would have been pleased with his team's start to the second half.
They were soon back in the game when striker Ben Strevens snaked past Wycombe's defenders before firing the ball low past goalkeeper Scott Shearer on 58 minutes.
But ten minutes later, Wycombe were ahead again with a goal that was a carbon-copy of their first. Williamson scored his second of the game with another dipping header, with Spence again the provider from a corner.
Dagenham nearly clawed their way back into the game late on when they put the home side under some pressure.
Strevens and Saunders both had chances to clinch a point for the visitors as Wycombe's defenders struggled against the onslaught.
And deep into stoppage time, Dagenham substitute Glen Southam won his side a spot-kick after being fouled by Wycombe's Chris Zebroski.
However, Strevens' penalty was wide of Shearer's post and it was Wycombe that sealed the points and yet another win as they look for promotion.