Heslop returned home with a gold and a silver medal from the championships and also the consideration score for next year’s Commonwealth Games in Australia.
The city teenager, who hopes to represent Wales at the Gold Coast event in April, won the men’s platform title.
He scored an impressive 465.35 points in the preliminaries before winning the final, ahead of Scotland’s James Heatly, with 393.15 points.
However, it was the score in the prelims, which was well within the Commonwealth Games consideration mark that had to be achieved by Sunday, which delighted Heslop.
“I didn’t really do anything different to what I usually do, it all just came right on the day,” he said.
“I’ve been close a couple of times but nothing like that score. It was great to do that this morning as I think it would have put too much pressure on me for the final.”
The Great Britain international also won a silver medal in the men’s platform synchro event with Plymouth team-mate Alfie Brown.
They finished behind Scotland’s Heatly and Lucas Thomson in the final. The Plymouth pair scored 320.10 in the final, which was a new personal best.
Brown also finished fifth in the men’s platform final.
There was also a silver medal in the mixed team event for Plymouth’s Swiss pair of Madeline Coquoz and Guillaume Dutoit.
They finished behind London Dive’s Grace Reid and Kyle Kothori.
Coquoz also finished sixth in the women’s three-metre final, while Kayleigh Sinclair was sixth in the women’s one-metre event.
Former Plymouth diver Robyn Birch won silver in the women’s platform event with 310.20 points.