Townsend played England 10 times from 1993-2003 and lost nine of those games, but under his management, Scotland have now won four and drawn one of the last six, with Saturday's success completing a hat-trick and marking the first time ever they have won back to back games at Twickenham.
"I felt a lot of emotion at the final whistle," Townsend told reporters after Duhan van der Merwe's late try snatched a victory that looked unlikely when England led 20-12 early in the second half and were turning the screw.
"I don't know if it's this fixture. I didn’t get close to winning as a player, it was always the same result down here. Two years ago (when Scotland won at Twickenham for the first time in 38 years) there was no crowd here so this was emotional.
"It was also the nature of the win - to come back and score that outstanding team try and then hold on at the end was brilliant. Just how you would want any test match to finish."
It was something of a smash-and-grab victory for the Scots, who struggled for possession but hammered into their tackles and kept their discipline from first minute to last.
They also looked the more dangerous side when they did cut loose, not least when Van der Merwe scored a fabulous 60-metre slalom try leaving five England defenders in his wake.
Townsend said it reminded him of the computer game version of the late former All Black Jonah Lomu "when he ran faster than everyone else. It was a fantastic turn of speed and balance. It was one that sends the Scotland supports crazy and silences everyone else as you don’t see tries like that very often," he said.
Despite his euphoria, however, Townsend was quick to remind everyone of his team's tendency to follow up victory with defeat - the main reason why they have failed to make any meaningful title challenge for more than 20 years.
"In terms of performance we know we are much better than that – we barely got anything going in the first half," he said.
"The consistent message coming through from the changing room was that this is nothing if we don’t get our recovery right, don’t train well and improve next week, and the players know that as we’ve previously not backed it up.
"In the last two Six Nations we've played Wales after beating England and haven’t won, so that’s the challenge for next week (when Scotland play Wales at Murrayfield).
"We have to be better - that wasn't our best performance. That's now the exciting thing for us, that we can grow more in this tournament."
