Heyward opened the 10th with an infield single off Francisco Cordero (1-4) and moved to second on pinch-hitter Jack Wilson’s sacrifice. With rookie Andrelton Simmons at the plate, Heyward took off for third base. Arencibia’s throw skipped past third baseman Brett Lawrie and into left field, allowing Heyward to score the winning run.
Cristhian Martinez (3-1) pitched a scoreless inning for the Braves, who remained one game behind first-place Washington in the NL East.
Jose Bautista homered for Toronto.
Toronto pitchers issued seven walks, including four to Dan Uggla.
Atlanta starter Brandon Beachy also was wild. He gave up two runs on three hits and a season-high five walks in five-plus innings.