Posh fielded a much-weakened side and were defeated 2-0 by a motivated Cheltenham side who kept themselves alive in League One with victory.
Posh are now set to finish fourth in the table unless they record an unlikely thumping of Bolton on the final day.
RATINGS KEY: 10-Out of this world, 9-Brilliant, 8-Excellent, 7-Very Good, 6-Okay, 5-Poor, 4-Stinker
5. JAMES DORNELLY
Another decent showing from the young full back. Tired towards the end before being replaced but battled well and times and tried to get things going with David Ajiboye on the right side. 6. Photo: Joe Dent
6. JADEL KATONGO
Deployed in central midfield with Kyprianou and Collins given the night off. Played incredibly deep, however, and struggled to provide any kind of creative spark. 5. Photo: Joe Dent
7. RYAN DE HAVILLAND
Would have hoped to show a lot more in a side filled with youngsters and makeshift players but did not impress. Made very little impact and gave the ball away for too often. Taken off first. 4. Photo: Joe Dent
8. MALIK MOTHERSILLE
Tried to make things happen but things did not come off. He played in an unfamiliar number ten role but played with energy and did more to make things happen than most. Played a nice pass for Clarke-Harris to volley at goal to force a good save. 6. Photo: Joe Dent