''Their four solo home runs proved to be the difference in the game,'' Houston manager Bo Porter said. ''They're definitely a power-hitting team.''
The Astros scored three times in the third to open a 4-2 lead. Grossman and Marc Krauss each hit an RBI single off Drew Hutchison, and Jason Castro had an RBI double.
Hutchison was charged with four runs and six hits in three innings. He is 2-5 with a 6.64 ERA in his last eight starts.
Gregorio Petit's run-scoring groundout gave Houston a 5-4 lead in the sixth, but Bautista tied it again with a sacrifice fly in the eighth.
Jake Buchanan started for Houston after scheduled starter Jarred Cosart was dealt to Miami earlier in the day. Buchanan allowed three runs and five hits in five innings.
Blue Jays: First baseman Dan Johnson was placed on the 15-day disabled list with a left hamstring strain. The Blue Jays recalled right-hander Chad Jenkins from Triple-A Buffalo.
Astros: Either outfielder George Springer, who has been on the disabled list since July 20, or Dexter Fowler, who has been on the DL since June 27, could go on a rehab assignment during the next road trip, which starts Monday, Houston general manager Jeff Luhnow said.
Left-hander J.A. Happ (8-5, 4.58 ERA) starts for Toronto on Friday against his former team. The Astros are sending right-hander Collin McHugh (4-9, 3.45 ERA) to the mound.
Toronto outfielder Colby Rasmus was scratched for being late to the stadium. ''I wasn't here when I was supposed to be here, and they punished me as they should have,'' Rasmus said. Anthony Gose started in center field, and Rasmus entered in seventh as a defensive substitution.
Houston acquired outfielder Jake Marisnick, infielder Colin Moran and right-hander Frances Martes as well as a 2015 compensatory draft pick from Miami for right-hander Jarred Cosart, infielder Kike Hernandez and outfielder Austin Wates.
Right-hander Brad Peacock, who was optioned to Triple-A Oklahoma City on Sunday, will likely take Cosart's place in the Houston rotation, Luhnow said.