KANSAS CITY, Mo. — A single, as defined by any other team, is a manageable and often acceptable outcome. It can be compensated for or worked around. But for the Kansas City Royals, who collect singles as eagerly as they might collect shells on the beach, those base hits that leave the hitter anchored at first base are the ones that can unspool a big inning.

On Friday night, it unraveled the Toronto Blue Jays’ season.

When the Royals’ Eric Hosmer lined a single down the right-field line in the eighth inning, Jose Bautista retrieved the ball and fired to second base, which served its purpose in keeping Hosmer at first. But the throw also allowed Lorenzo Cain, who never hesitated, to race all the way home from first with the decisive run as the Royals beat the Blue Jays, 4-3, to clinch a berth in their second consecutive World Series.

“It was a gamble,” Blue Jays catcher Russell Martin said. “Unfortunately for us, it worked out for them.”

Cain’s derring-do was matched in the ninth by that of closer Wade Davis, who escaped runners at second and third and nobody out by getting a pair of strikeouts and inducing Josh Donaldson to ground out, setting off a celebration.