The Uruguayan's 35-yard chip to secure the three Premiership points against the Rams was the 100th league goal since moving to Europe from River Plate to Real Zaragoza in 1990.
With the clock ticking into injury time on Monday night, Rams defender Youl Mawene stumbled and, without taking a touch, Gus swooped on the loose ball and lobbed home first time over giant keeper Ian Feuer.
It was his first league goal since his summer switch from Chelsea and he was ecstatic about it.
"It's a goal I've been dreaming of for a long time," he said. "I've haven't been able to score yet, I've had a lot of tries, but they've gone over, been saved or hit the post so when it went in I was very happy.
"When he lost the ball I hit it first time but the problem was the keeper didn't move and I thought perhaps it was over. When it went in, 'lovely'!
"I have a good record and I wanted to start scoring. When I scored at Tranmere, that was important because it gives you confidence and, the way we played against Derby, you will always have chances.
"It is totally different to the one I scored (for Chelsea) against Sunderland, the scissor kick, but I enjoyed it. My first one at White Hart Lane. It's in the top five, for sure."
And Gus seemed happy to be part of a wonderful team performance with the movement and passing, particularly in the first half, right out of the top drawer.
Gus added: "It was a magnificent performance, the first half absolutely top class. There was great movement and the second goal was absolute class.
"That's what we were looking for - play well, score goals, three points.
"From now on we need to try and keep that level. I know we have a couple of difficult games coming up but we are confident."
Gus Poyet has completed a magnificent century - and immediately placed his delightful goal against Derby County in his personal top five.