The team apologized to fans Tuesday night after the roof was unable to close at the normal speed, leaving many people opening umbrellas to protect themselves from the elements.
Groundskeepers had to use drying agents on the mound and dirt cutouts around the bases before the bottom of the sixth inning as rain continued to fall on the infield.
The roof was closed when the game began but opened in the third. It started closing again in the fourth, but the final two panels were still about 30 feet apart in the seventh.
The Blue Jays had a 26 minute delay in July 2003, when a sudden storm drenched the field before the roof could close during a game against the Chicago White Sox.
Toronto broke a 31-year record for rainfall Tuesday, as the remnants of Hurricane Isaac dumped more than 1½ inches of rain on the city by 2 p.m. Showers continued into the evening.