Sheffield United's hold on an automatic promotion place was loosened by a draw with Tranmere Rovers.
The Blades led just after the half-hour mark when Ched Evans scrambled home after good work from Stephen Quinn.
But Lucas Akins headed home John Welsh's corner nine minutes into the second half to level the scores.
Chris Porter and Neill Collins both had chances for the Blades, but their headers were kept out by Rovers keeper Owain Fon Williams.
The result leaves the Blades only above city rivals Sheffield Wednesday and the play-off places on goal difference - and nine points off leaders Charlton.
VIEWS FROM THE DRESSING ROOM
Sheffield United manager Danny Wilson told BBC Radio Sheffield:
"We had a lot of situations today we've not been able to force the ball over the line for that second goal.
"It does happen, you can't be down about it, but you want to win you're home games.
"I think we've had enough chances to out the game safe, but we couldn't force the ball over the line."
Tranmere manager Ronnie Moore told BBC Radio Merseyside:
"It was a great performance from the lads, everyone expected us to get beat and this was one of our bonus points I think.
"What we lack in the ability that they've got, I think, we had more desire, and a willingness to run, chase and harry and that's when you get your rewards.
"We've got to do it all again now on Tuesday and you don't get a breather. Rochdale are near the bottom of the league and Sheffield United are near the top, so it will be just as hard or even harder."