Bad /good news

[steplift20]

I filled my boat up with gas for winter. And gas started spilling out of my hull drain plug area , not good but it stopped after about a gallon came out. The good news is I found out there was a problem on land and not in the water. God forbid there was a spark. ***128293;. So what I’m thinking is it’s leaking somewhere from the top,possibly the hose fill where it attaches to the tank. I hope it’s not the tank,it’s a plastic tank.
Any suggestions?