Stamper beat long-time rival Vladimir Kim to win the featherweight title, securing his second Open victory of the season, fuelling hopes he could upgrade his 2011 bronze in Mexico later this summer.
"I didn't put any expectations on myself fighting here as we are in a heavy faze of training in preparation for the World Championships in July," he said.
“But I am really happy with my performance. I had five tough fights against some quality opponents and felt pretty comfortable in each fight.
“I feel my game has improved so much on the Daedo scoring system and that is down to hard but clever work in training."
But Walkden was certainly made to work for her victory, beating France's Gwladys Epangue on sudden death to win the heavyweight title.
“I’m so happy to have picked up another title. It’s been great preparation for the World Championships and it felt like a ‘mini-Worlds’ given the quality of opponents," she said.
“I just hope I’ll be on the podium in Mexico and I’m going to go back to the Academy and train will all my heart.
“I’ve picked up a few good things to work on and I’m just going to commit. I want to be unbeatable.”
Olympic champion Jade Jones settled for bronze in the women's featherweight, losing to home favourite Eva Gomez, while London 2012 bronze medallist Lutalo Muhammad, in his first competition since last year's Games, also claimed third in the men's middleweight.