Coutya had won silver and three bronzes, including one in this event, at the Tokyo Paralympics.
He opened up his competition with a 15-7 win over American Noah Hanssen before defeating Italy’s Michele Massa 15-10 in the last eight and a 15-13 success over Poland’s Michal Dabrowski in the semi-final.
At 7-7 in the final against Kingmanaw he went on to win six of the next points and take control of the bout.
But Coutya admitted he did not have things all his own way in his earlier contests.
“At one point in my first round match I was convinced I would be out because I was struggling and wasn’t feeling it,” he said.
“But we have put in a lot of work to being as consistent as possible even when you are struggling and I found my form as the day went on and it has culminated in a gold medal
“I’m so thrilled. It hasn’t really sunk in yet.
“I think it is testament to the hard work that so many people have invested in me – team-mates, support staff, friends and family and there are so many people here supporting me and pushing me to be better and they are a large part of the reason why I have been so successful this week.”