Posh were pitiful at Priestfield in the first-half before turning on the style with three goals in the first 21 minutes of the second-half.
There were some dogged defensive displays before the break before the attacking players strutted their stuff after the break.
RATINGS KEY: 10-Perfect, 9-Outstanding, 8-Very Good, 7-Good, 6-Okay, 5-Poor, 4-Very Poor.
9.
SAMMIE SZMODICS: A forlorn figure until Posh got to the grips with the opposition tactics and the conditions. He came alive to great effect to help the Posh comeback with some fine passing and running. Excellent on the counter attack 7.5
10.
JONSON CLARKE-HARRIS: Hardly had a kick in the first-half, but his striker's instinct enabled him to pounce for the equaliser and his flick for the third goal was a thing of beauty. Another powerful second-half display from the big man 8
11.
MO EISA: He was no worse than any other attacker until his half-time substitution, but Dembele's arrival lifted the team and frightened the life out of Gillingham 5.
12.
SIRIKI DEMBELE: His arrival, as well as the change of shape, was the catalyst for a dramatic improvement. Too skilful and too quick for these opponents. He started and finished the move which gave Posh the lead early in the second half 8