He converted his first match point in the deciding tiebreaker to clinch his third ATP title.
The 33-year-old Spaniard came back from a set and a break down to secure the victory at the clay-court tournament. He is 16-5 on clay, which is the best record on the surface this season.
"I won three tournaments in my career, so this is one of the best three weeks in my career," Ramos-Vinolas said. "It was a really difficult match against Cameron. I think he played a really good tournament."