The Republican contest on the island territory has 20 delegates toward this year’s GOP nomination for president.
Romney will get all 20 after capturing more than 50 percent of the vote, bringing him to over 500 delegates but still fewer than half the 1,144 needed to clinch the nomination.
Santorum stood at a very distant second, with just 8 percent, according to CNN, which said that Newt Gingrich and Ron Paul were barely blips on the radar, with two percent and one percent respectively.
The results confirmed what appeared to be the latest conventional wisdom before the vote, which had Romney as the favorite among Puerto Rican Republicans.
Santorum had appeared to be the victim of his own aggressive attitude this week, insisting that Puerto Rico adopt English as an official language in order attain statehood, according to USA Today.
Govenor Luis Fortuno and most prominent island Republicans had endorsed Romney, according to CBS News.