The 25-year-old took Olympic silver in Tokyo but hasn’t won major gold in the four-stroke event since the 2014 European Junior Championships.
Scott ticked that box on the final night of swimming at Sandwell Aquatics Centre, defying Dean in a thrilling head-to-head.
He said: “The rivalry or competition in general gets the best out of us. I can say that for myself and definitely for Deano.
“We love a race, whatever the competition. We love the atmosphere, we love finals, and we love getting in amongst it.”
Scott and Dean’s Olympic final rematch in the 200m freestyle was given top billing, coming on the second day of the Games, with the Scot reversing the result from Tokyo.
But their multi-stroke duel on the final night of racing was just as box office and three times as close, going in Scott’s favour by 0.13s rather than 0.39.
Both Brits conceded ground to Canada’s Finlay Knox on the backstroke leg but Scott used his butterfly strength to fly from fourth to first at the halfway mark.
The Glasgow star held his advantage on breaststroke and then held on despite Dean outsplitting him by more than half a second coming home.
Scott got it at the touch in a time of 1:56.88.
“I knew he was there, I was like, ‘oh, he’s catching,’” admitted Scott. “Obviously I was breathing the other way, we both breathe to our right.
“I know I’m a lot better on other strokes but he comes home strong, he’s faster than me on the freestyle. But Tom, great racer, great competitor. I knew he’d be coming home fast.”
Scott dived back in and helped Scotland win bronze in the 4x100m medley relay.
For Craig McNally and Ross Murdoch it was their final act in the pool and quite a way to go out, on the podium behind England and Australia.
It has been a brutal meet by Scott’s masochistic standards, consisting of 11 races in five days, and even the man with the endless engine was blowing by the end.
He said: “Tonight was more of a grind but this one is up there. Honestly, I’m just absolutely exhausted and I was really hurting in that race.”
National Lottery players raise more than £30million a week for good causes including vital funding into sport – from grassroots to elite. Find out how your numbers make amazing happen at: www.lotterygoodcauses.org.uk and get involved by using the hashtag: #TNLAthletes