Gannon was delighted with the way in which the Posh side performed in coming from a goal behind to beat Roy Keane's side on Tuesday evening.
The 3-1 win at London Road moved Posh to within nine points of their 21st placed rivals in the Championship table.
"In the second half we had more tempo and certainly did enough," the Posh boss said after the game.
"I just reminded them at the break about what we have been working on and we played my way after the break.
"I have learned a lot in my short time here and if we play like that for the majority of the remaining games then we will give ourselves a chance."