The Robins fell to another late defeat in Sky Bet League One action, as they were beaten 2-1 by Oxford United at the Kassam Stadium.
Josh Murphy opened the scoring for the hosts moments before the interval, but Will Ferry's equaliser 10 minutes from time looked to have earned Town a point.
But defender Greg Leigh was on hand at the back post to head home Owen Dale's cross two minutes from time to send the Robins home empty handed.
After the defeat, manager Darrell Clarke said:
"I'm angry at the end of first half and the ending of the game. It's a mindset thing and a mentality thing that I won't accept.
"We can't feel sorry for ourselves, we can't become victims, we have to just get better."
It was the hosts that would take aim at goal first in a fairly quiet opening 45 minutes, Ruben Rodrigues working the space before dragging his effort wide of the near post.
The Robins had their best chance of the half not long after, this time some good football from the visitors saw Aidan Keena set Liam Kinsella, but he could only fire wide from the edge of the area.
Oxford began to get more of a foothold in the game toward the end of the half and saw their first effort on target well saved by Luke Southwood, as he got down well to stop Mark Harris low strike.
But in one of the last actions of the half the hosts had their goal, as Murphy breezed past a few Town defenders before firning home into the bottom left corner.
After the break the Robins made numerous changes, bringing on the likes of Jordan Thomas and Greg Sloggett who provided a new-found energy.
Thomas tested Cumming on 73 minutes after a briliant challenge from Kinsella. The youngster took aim, but it was comfortable for the Oxford number one.
The Robins did get their equaliser 10 minutes from time however. As the ball dropped to Ferry on the edge of the area, he managed to sneak his effort past Cumming into the same corner which Murphy found earlier in the afternoon.
But from the goal the hosts took it up a gear and in the 88th minute they found a winner. Dale did well to beat Ferry and hang a cross to the back post where Leigh was on hand to break Cheltenham hearts late on once again.
OXFORD UNITED (4-2-3-1): Cumming; Stevens, Moore (C), Brown, Leigh; Brannagan, McGuane; Dale, Rodrigues, Murphy (Bodin 90+); Harris (Goodwin 67). Subs not used: Eastwood (Gk), Bennett, Henry, Matete, Thorniley
CHELTENHAM TOWN (3-5-2): Southwood; Davies (Smith 70), Bradbury, Shepherd; Long (C), Sercombe (Harrop 57), Pett (Sloggett 70), Kinsella (Bonds 83), Ferry; Nuttall (Thomas 57), Keena. Subs not used: Pardington (Gk), Williams
REFEREE: M Edwards
ATTENDANCE: 8,738 (643 from Cheltenham)
