Oxfordshire rallied on day two of their Minor Counties clash with Devon to build up a lead of 261 runs.
After being bowled out for just 76 in their first innings, Oxfordshire reached 367-9 at the close on Monday.
Charlie Knightley was the top scorer for the visitors, hitting 89 off 209 balls, while Daniel Rowe made 84.
Devon go into the final day with one wicket still to take, before hoping they can improve on their first innings total of 183.
Chris Metters was the pick of Devon's bowlers in Oxfordshire's second innings, taking 3-73 from 35 overs.
Devon's director of coaching Roger Newman said: "Hats off to Oxfordshire, they batted with concentration and determination and the day belonged to them.
"The pitch has eased considerably since Sunday and it was pretty obvious we weren't going to bowl them out cheaply again.
"Because we did so well ourselves on the first day we remain in a good position to win the game."