Jay Saunders hailed his FA Cup heroes after Maidstone upset League 2 Cheltenham.
United won 4-2 at Whaddon Road on Saturday as Saunders' side reached round two for the second time in four seasons.
Stones felt Town might be vulnerable at the back, racing into a 3-0 lead at half-time through Delano Sam-Yorke and Joe Pigott and Zavon Hines.
Sam-Yorke scored Maidstone's fourth but was later sent off and Town went for the jugular before being reduced to 10 men themselves.
Saunders said: "For the first 45 minutes, it's shown what we're capable of and I'm delighted with the boys.
"When you come into games like this and you're playing teams above, you need everyone on their game, you need them to take on board what you're asking them to do.
"We went through things this week with them and they've taken it all on board and gone out there and done it.
"The first half was such a very professional performance and, if anything, I'm disappointed we didn't nick a couple more goals.
"Second half was difficult. The sending off kind of changed the pattern of the game a little bit but the boys dug deep.
"To come to a League 2 club and really control the game, we speak to the boys about game management, about slowing things down, about doing the right things.
"If you look at that first half, other than probably the first five minutes where they've had a couple of chances at the far stick, it was mainly us.
"We dealt with what they had to throw at us and at the other end looked a real threat every time we went forward."
Maidstone worked on exploiting Cheltenham's defence and it paid off spectacularly.
Saunders said: "We felt our front three could cause them problems.
"I don't want to sound disrespectful but that was an area we thought we could cause them problems and we worked on areas we could get in and we did that early on.
"We'd worked on stuff with them and, like I say, the boys were outstanding and it was a really good performance.
"To come here and score four goals against a league side speaks volumes of the performance."