Uribe led off the inning with his 14th home run of the season and Renteria added a two-run shot to give the Giants their fifth win in their last six games.
Both homers came off reliever Brian Sanches (0-2) who worked just one inning and was tagged for three runs on three hits to take the loss.
Buster Posey had an RBI single for San Francisco and extended his hitting streak to 20 games.
Sergio Romo (4-3) picked up the win in relief of Matt Cain. Brian Wilson recorded his 30th save.
Dan Uggla had two solo home runs and Cody Ross notched a two-run homer to lead Florida's 5-hit offense.
Uggla tied the game 3-3 in the seventh with his first home run of the night and 20th of the year. His second came in the ninth after San Francisco had grabbed the late 6-3 lead.