Wycombe caretaker manager Gareth Ainsworth admitted his hopes of taking over the hot-seat on a permanent basis had been dealt a blow after watching his side beaten at home by Oxford.
Tom Craddock set up the first for James Constable before the U's striker grabbed one for himself - firing home his fifth in three games at the start of the second half. Joel Grant instantly pulled one back from the penalty spot but Johnny Mullins headed in a third for Oxford for their first league win on the road since August.
Wycombe co-chairman Don Woodward admitted before the match the job would be Ainsworth's if he kept their recent good run going but the interim player-boss accepted the performance against Oxford had done him few favours.
"It's probably a bit of a whack on my CV, but we'll try and turn it round," he said. "Losing one in six up to today has been very good and we'd been playing very well and defending very well - we were confident going into this. It's a dent but there's no news on a managerial decision.
"There aren't too many positives from today. It's just one of those things where the lads are going to be very down after it, but they should be. We'll remember this and we can get back to the mentality of the three games we won as opposed to feeling like this.
"It was a proper derby game. There was a lot of tackles flying in but their early goal gave them a boost and settled them down.
"We didn't really start playing until 30 minutes in. We started playing well but losing another sloppy goal two minutes into the second half was killer. We got one back but it was always an uphill struggle."
Wycombe failed to cope with the threat of Constable and Craddock and it was no surprise when the pair combined for the opener, with Craddock then continuing his fine run goalscoring run with the second.
And after a slow start to the season, Oxford boss Chris Wilder claimed the pair had proven they had sufficient firepower to get the U's climbing the table. "Strikers get judged on goals and it was great to see them both score," he said.
"But their overall play was good as well. Going forward we maybe could have moved the ball a bit better and I was possibly disappointed we didn't get a couple more but generally I thought we dominated. It was a whole team effort, everyone played well."