Wycombe ended Oxford's 100 per cent home record by holding their local rivals to a goalless draw in front of a packed Kassam Stadium.
In a fiercely-contested match, Wycombe edged the first half in terms of chances but the home side bossed the second half.
Cameron Brannagan screwed an angled shot across the face of the goal for Oxford early on.
But Wycombe were lively going forward and after U's midfielder Alex Gorrin produced a vital block, Jordan Obita brought a good save out of Jack Stevens.
Stevens made an even better one-handed save to turn a Sam Vokes drive over the bar after a quick Wycombe break.
Luke McNally headed a corner over and Brannagan gave David Stockdale a tester with a shot that bounced just in front of the Wycombe keeper.
The home side's pressure increased through the second half and Anthony Stewart needed to clear off his line to prevent Mark Sykes' pull-back being turned in.
But neither side could find a breakthrough as tempers flared several times.