Munton, who missed the whole of last season while recovering from back surgery, pulled up with a tweaked hamstring midway through the morning session. He could be out of action for a fortnight.
A career-best 73 from Jason Molins led a creditable Oxford reply to Warwickshire's first innings of 307 for 7, as the students declared at 269 for 9 off 93 overs. Warwickshire scored a rapid 64 without loss off 13 overs before the close.
At Fenner's, Durham closed on 186 for 1 in their second innings, 337 ahead of Cambridge University, who were dismissed for 119 in their first innings.Reuse content