The loss dropped Boston into a tie with the Yankees for the AL East lead.
Masterson (9-7), traded by Boston to Cleveland in the Victor Martinez deal in 2009, raised his Fenway record to 10-2. He is 15-33 everywhere else. He is also 3-0 against the Red Sox.
Masterson also tied a major-league record with four strikeouts in the third inning. He is the sixth Indians pitcher, the first since Chuck Finley in 2000, to fan four in an inning. Masterson's wild pitch prolonged the inning.
Erik Bedard made his Red Sox debut after being acquired from Seattle, and gave up three runs and seven hits in five innings.
Rays 7, Blue Jays 6: Robinson Chirinos hit a tying pinch single in the 11th inning, then delivered a two-out single in the 12th to lift host Tampa Bay. Jose Bautista hit his major league-leading 33rd home run for Toronto.
Cardinals 7, Marlins 4: Albert Pujols hit his 25th home run and finished a triple shy of the cycle for visiting St. Louis. Marlins second baseman Omar Infante broke his right middle finger diving for a grounder in the third inning. He left the game in the sixth. Cardinals third baseman David Freese suffered a mild concussion and a bruise when he was hit in the helmet by Clay Hensley in the third.
Cubs 7, Pirates 6: Carlos Peña hit one of visiting Chicago's three home runs and walked with the bases loaded during a three-run eighth-inning rally as the Cubs won their season-high fifth straight. The Pirates have lost 9 of 10.
Molina suspended 5 games
Cardinals catcher Yadier Molina was suspended for five games after bumping an umpire several times and spraying him with spittle during a run-in this week -- AP