Derby County coach Frank Lampard described his team's FA Cup victory in Southampton as "magical" after the championship team had won 2-0 after a penalty shoot-out.
Derby had had to exclude a goal in the first half of VAR, but with two goals in six minutes a quarter-round trip to Accrington was launched.
"It takes a lot of time to return to the opposition in the Premier League and show this fight," said Lampard.
"They made me proud."
Craig Bryson was of the opinion that he had brought the Rams forward in the first half, but his goal was knocked over offside - a decision that former England international Alan Shearer, who spoke of Match of the Day, considered "very difficult made ".
Southampton then scored two goals in two minutes from Stuart Armstrong and Nathan Redmond for a 2-0 lead. But as in the first game eleven days ago, the outsiders have beaten back thanks to the goals of Harry Wilson and Martyn Waghorn.
Saints Sub Redmond missed his penalty on penalties, allowing derby skipper Richard Keogh to convert the winner to more than 1,000 traveling fans.
"It was easy to give up in a 2-0 deficit and they did not make it," said Lampard, who had won four FA Cup finals with Chelsea, to BBC One. "I have a really good changing room with great characters, they wanted to play, run when tired, and we deserved to win the game.
"I'm happy for Richard Keogh, everyone in this club knows how important he is, the club means so much to him, he asked to take one, I know he has quality, he is a man of strength who Kind of man that you want to take
"Big thanks to the fans, because it's half past nine when the game is over, they'll return to Derby anytime, and they're probably working on Thursday too, so a big thank you to them for helping us out the line."
Southampton coach Ralph Hasenhuttl said his team did not deserve to progress, and felt the Rams' comeback hit their players and crowd.
He told BBC Sport, "Congratulations to Derby County, and if they fight like in the two games, they deserve to go to the next round.
"They got a goal from a set-piece and you could feel that everyone is thinking about the first game and getting a bit nervous."