Jack Powell, Danny Kedwell, Chris Bush and Myles Weston were on target as Fleet brushed Guiseley aside on Saturday.
It was Fleet's first 4-0 victory in Non-League's top tier since beating Stevenage by the same scoreline back in 2008.
Saturday’s success moved McMahon’s men up to tenth and just four points adrift of the top seven.
Fleet have bounced back well from the defeats at Wrexham and Woking with home victories over Hartlepool and Guiseley and McMahon is pleased with his side’s progress.
The boss told BBC Radio Kent: "It was a good win. We were very clinical in front of goal, we defended pretty well and I thought we caused them a threat.
"They didn't have a lot of chances if I’m being honest, I thought Nathan Ashmore had minimal stuff to do today.
"We're just learning and evolving as a team and getting people on the pitch a bit longer in terms of consistency. We're getting a settled team and it is important.
"We've still got loads to improve on, we know that, but we'll see where it takes us. I'm not going to make any predictions, all we want to be is competitive and so far we are."
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