Chris Wilder admitted Steven Craig's early sending-off helped his side as Oxford claimed a 1-0 M40 derby victory at Wycombe.
Wycombe were left facing an uphill task when Craig was sent off for violent conduct after just 20 minutes for jumping into Johnny Mullins.
Yet the Chairboys held out for most of the game and could have won it through Gary Doherty, only for Nicky Wroe to fire home a winner three minutes from time.
And Wilder sympathised with opposite number Gareth Ainsworth, who he felt had every right to blame Craig for their defeat.
"It's not our fault their lad's come and tried to smash Johnny Mullins in the face. It was absolutely blatant and I have no change of opinion on that," said Wilder.
"In a league derby we know they are going to be wound up, they are going to be enthusiastic. Sometimes players step over the line and let their manager down and their player has done that and made it doubly difficult for their team to get a result.
"Credit to Gareth and his team they were stubborn, they sat deep, they made it really difficult for us but it's a vital win.
"We had a lot to lose with our league position and our fantastic record. And it's their big derby which we had to respect.
"We had to be patient, we did that and we got our rewards.
"He (Wroe) has given everyone a lift. His attitude's great, he's a good footballer and he weighs in with some goals."