Promoted Chesterfield edged another point closer to the League Two title with a draw at Oxford.
The U's had the better chances and winger Alfie Potter saw two second-half efforts saved by Spireites goalkeeper Tommy Lee.
And visiting captain Dwayne Mattis made two superb blocks to ensure his side kept a clean sheet.
Victory against promotion-chasers Bury at home on Monday will hand Chesterfield the trophy.
Chesterfield boss John Sheridan told BBC Radio Sheffield:
"It's been a long season and we've been in a position where everyone thought we were going to get promotion and I've said it a few times. I didn't mention it too much myself, but in the back of my mind I thought we are in a good healthy position to do it.
"I'm just pleased for the players and obviously the club. We're a club who's trying to go forward, the players are the ones who need patting on the back because the 18/19 players who I've used and that's been the biggest thing for us this season, the strength and depth.
"If we've got players who are comfortable and who can get in and score goals in dangerous positions, we might as well play to our strengths and I think we've done that especially at home I think we've been very entertaining."