With the win, Canada also earns a spot at the 2014 world championship in Turkey for a third consecutive time.
Mission, B.C., native Kim Gaucher led Canada (5-0) to its fifth straight victory at the FIBA Americas tournament with 14 points, 11 rebounds and three assists.
Though she's pleased with the result, the veteran of Canada's women's program knows the win is just a step toward the team's ultimate goal.
"It feels great, but it feels like we're not done yet," said Gaucher. "We came here to get the gold, not just to qualify so it feels like we still have a job to do right now.
"We truly feel like we're a team on the rise and we're a force to be reckoned with in women's basketball. To continue what we've been doing in the last few years, we knew we couldn't just come here and not play our best and not qualify ... We feel like we're good enough to be in the finals and that's what we came here to do."
The Canadians will play Cuba for gold on Saturday.
Canada opened up the contest with a late 12-0 run to lead 26-8 after the first 10 minutes of play. Puerto Rico outscored Canada 18-13 in the second quarter to cut into the lead, but the Canadians held a 39-26 advantage at halftime.
Puerto Rico continued to apply pressure in the third, trimming the lead to single digits on two occasions. Canada finished the third with a 10-1 stretch to go ahead 58-40, and closed-out the match by holding Puerto Rico to eight points, while scoring 15.
Natalie Achonwa of Guelph, Ont., added 11 points and 10 rebounds for Canada, while Brampton, Ont., product Tamara Tatham tallied 10 points and seven rebounds as Canada out-rebounded Puerto Rico 49-23.
"Us winning this game is almost a relief — so much excitement — but also a relief that we did qualify," Achonwa said. "To be able to get rid of the jitters of qualifying and now to play for the gold, it will be a great experience."
Carla Cortijo was the top scorer for Puerto Rico with 22 points.
Cuba, meanwhile, advanced to the final by upsetting Brazil 72-68 on Friday.
Clenia Noblet scored 18 points for the Cuban squad while Leidys Oquendo added another 17. With 15 points, Adriana Pinto was Brazil's top scorer.
The top three teams from the tournament advance to the 2014 championship. Puerto Rico will face Brazil on Saturday for the bronze medal, and the final spot in Istanbul.
Canada has not reached the final of the FIBA Americas since hosting an Olympic-qualifying edition of the competition in Hamilton in 1995. The Canadians went on to win gold in that tournament to earn a spot at the 1996 Summer Olympic Games in Atlanta.