Goals from Cody McDonald Joe Martin and Adam Barrett moved the Gills off the foot of the League One table and up to 17th place with their first three points.
"I think that's reward for all the hard work the players and staff have put in," Allen said. "We've trained for five days this week, done a couple of afternoons and the players have all put in a big contribution off the field.
"I thought they played very, very well. It was very similar I thought to how we played last year - the same team spirit, unity and togetherness.
"The performance was down to the extra training and the team spirit.
"Obviously something had to be done - we couldn't carry on like we were doing, and that's what I do. It may upset a few people, but the results weren't there anyway so there's no worries about upsetting anyone.
"It's about making our supporters happy, putting in good performances. All of the players were quality."
Allen continued: "I don't think I've ever put on as many training session in one week in all my life. It was back to basics, and the players carried it out to a T.
"We don't get carried away, though, we just do our job. Just like last week, we won't go down to the chemist to get some medicine and this week we won't have any champagne."