Welling saw their first half advantage wiped out as Maidenhead hit back with two second half goals to take the points on Saturday.
Ross Lafayette (pictured) gave Welling the lead with a goal after 15 minutes in the Blue Square Bet South match.
Welling were aiming to bounce back from last weekend’s 3-1 FA Cup defeat to Bishop’s Stortford but were unable to hang onto their lead at Maidenhead.
The hosts levelled the scores just before the hour mark, through defender Mark Nisbet, after keeper Sam Mott had spilled a cross.
And Nisbet put Maidenhead ahead with 71 minutes gone.
Scott Kinch came closest to levelling the scores, with a shot that flew wide, but his afternoon was cut-short as a second yellow card three minutes from time led to his dismissal.