Ryan Cresswell grabbed a last minute winner for Rotherham over Cheltenham.
who announced the appointment of Steve Evans as their new manager earlier on Monday,
missed a first-half penalty when Jack Butland saved Lewis Grabban's effort.
Kaid Mohamed and Josh Low both went close as the visitors improved after a poor first-half showing.
Cresswell rose highest to head home Ben Pringle's corner to hand the hosts victory at the death.
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Rotherham United caretaker manager Darren Patterson told BBC Radio Sheffield:
"I thought we dominated possession, they showed what a good side they are in the second half.
"I'm proud of the way the lads have performed and the staff have stuck together.
"I bumped into the new manager at the hotel (this morning) and wished him and his assistant every success and hope that he's a success for Rotherham United."
Cheltenham Town manager Mark Yates told BBC Gloucestershire:
"It's disappointing with 30 seconds to go in added time to lose it but they probably got what they deserved.
"I thought they were good in the first half, but in the second half we were more like ourselves.
"But we go again. I'm not too angry, we're all disappointed but we've got four games left and it makes those games even more important.
"I don't have any doubt we can hold our nerves, we're disappointed to get beaten today but there's 12 points to play for and we're in the box seat."
Rotherham United 01 Taylor 02 Tonge 05 Cresswell 17 Mullins 07 Evans (Hoskins - 72' ) 08 Taylor 11 Schofield 18 Pringle 26 Wood 09 Revell (Cadogan - 79' ) 23 Grabban Substitutes 21 Warrington 03 Newey 04 Harrison 28 Cadogan 10 Hoskins Cheltenham Town 12 Butland 02 Lowe 06 Elliott 15 Bennett 19 Garbutt 16 Penn 20 McGlashan (Low - 60' ) 25 Summerfield 14 Spencer (Duffy - 80' ) 23 Mohamed 29 Burgess (Smikle - 46' ) Substitutes 24 Hooman 08 Low 11 Smikle 09 Duffy 30 MacLean