Luton Town boss Paul Buckle has described his side's win at Premier League Norwich City as "incredible".
The Hatters' fourth-round victory was the the first time a non-league side has beat a top-tier team in the FA Cup since Sutton beat Coventry in 1989.
"It's an incredible performance from the players," said Buckle.
"I'm absolutely delighted for the players. The fans were out of this world, we probably couldn't have done it without 4,000 supporters here."
Luton had already beaten Championship Wolves in the previous round to set up the clash at Carrow Road.
And the Hatters, 85 places below the Canaries on the football ladder, went through thanks to substitute Scott Rendell's strike 10-minutes from time.
"I don't normally get that excited on the sidelines," said Buckle. "But the faces of the substitutes and staff was a real picture. It was amazing.
"I watched the players celebrate the goal. I was a little concerned they celebrated too long and would be washed out by the time they got back to the halfway line.
"We knew there would be a response from Norwich and we had to brace ourselves and trust the work we did."
Buckle's previous biggest success as a manager was taking Torquay United out of the Blue Square Bet Premier in 2009 and leading the Gulls to a League Two play-off defeat by Stevenage in 2011.
But becoming the first non-league manager to beat a top-flight side in the Premier League era will now rank alongside those achievements.
"I've been fortunate in a few years of management to have some really good highs. This is right up there. It's an incredible achievement by the players," said the 42-year-old.
"Against Wolves and Norwich there was no fluke about it. We weren't holding on for dear life.
"After that experience we'd dearly love to play a Premier League club again. This is where everyone wants to be."
Luton striker Stuart Fleetwood believed his side excelled because the pressure was off them against their higher-placed opponents.
He told BBC Radio 5 live: "We were playing away in front of 26,000 fans but the pressure wasn't on us. When we're at home in the league it is and it was nice to be the underdogs for a change. I think it showed in the way we played.
"The players are buzzing - we are having a couple of beers. But it's back down to Earth on Tuesday night because we're playing at Grimsby in the FA Trophy. So there won't be too much celebrating."
Norwich boss Chris Hughton, however, was left to reflect on the most sobering defeat of his managerial career.
The Canaries have now lost six of their last eight games and will attempt to turn their attention to Premier League survival and Wednesday's game against Tottenham.
"It is probably right up there as one of my worst moments," said Hughton, who was a team-mate of Buckle's in their playing days at Brentford.
"The game us full of highs and lows. If you look at our form it's very much taken a dip. We're in a difficult place at the moment and possibly the scoreline is a reflection of that.
"What's more important is that we come out of it as quick as possible. But at this moment it's not a particularly nice feeling and you want to get over it as quickly as possible."