What phrase names a home-team home run that immediately ends an MLB game?

A home-team home run that immediately ends an MLB game is called a walk-off home run.

It occurs when the home team hits a home run in the bottom of the final inning and takes the lead. Because the visiting team has no remaining opportunity to bat, the game ends immediately and the defeated defense can walk off the field.

The winning run must still touch all three bases and score at home plate. If the bases are loaded, the play is specifically a walk-off grand slam, which scores four runs and is a special type of walk-off home run.

The phrase “walk-off” became widely popular in the late 1990s and early 2000s, although an early printed use appeared in the San Francisco Chronicle in 1988. It should not be confused with a lead-off home run, which begins a team’s turn at bat, or an inside-the-park home run, which describes how the ball is hit rather than when the game ends.