On a baseball broadcast tonight, the team statistic "wins in last at-bat" came up. What's the definition of this term?
The announcer was careful to point out that such a win "doesn't have to be a walk-off", and gave as an example San Francisco at Milwaukee, June 8, 2017. This was an extra-innings game in which the visiting Giants scored four runs in the top of the 10th, then held the Brewers scoreless in the bottom of the 10th to win. But the Giants' last at-bat in the top of the 10th didn't score a run at all (it was a ground ball into a double play) so it's not clear to me in what sense they won on their last at-bat.
If it helps, there was a graphic showing the National League leaders for most wins in last at-bat in the 2017 season up to June 9:
Giants 9 Phillies 9 Diamondbacks 7 Braves 7
I tried searching and found a few mentions of games won on the last at-bat, but couldn't find a precise definition.