SAN FRANCISCO -- If only Aroldis Chapman had known what Conor Gillaspie was going to say more than two hours later, maybe none of this absurdity would have happened.

Then again, you could say the same thing for Ralph Branca or Dennis Eckersley or Clayton Kershaw or any other pitcher who has been hit by one of those late-inning jolts that comes out of nowhere and lodges forever in our memories from a great postseason baseball game.

Facing the hardest-throwing pitcher he had ever seen in his life, Gillaspie, not surprisingly, completely sold out on velocity.

“You pretty much get on the fastball,” Gillaspie said. “If he throws you something else, you’re in trouble.”

So, that is the start of the explanation for, perhaps, the most improbable event in a seemingly endless string of them that turned into the San Francisco Giants’ thrilling 6-5 win to avoid elimination in Game 3 of their National League Division Series against the mighty, but suddenly mortal-seeming Chicago Cubs.

Gillaspie, a left-handed hitting bench guy signed to a minor league deal, turned on a 102-mph fastball from Chapman, probably the hardest-throwing pitcher in major league history, and who, by the way, throws left-handed.

Madison Bumgarner, who knows a few things about lefty-on-lefty platoon advantages, described the degree of difficulty.

“That’s about as tough as it gets,” he said. “But Conor can hit, man.”

Gillaspie got on the fastball. He got on it so hard, he sent it screaming toward triples alley, where the right-field wall here juts out to 421 feet. Gillaspie’s two-run triple spurred a three-run Giants rally that, in turn, forced a two-run Cubs rally that, in turn, sent the game spinning 13 innings. And that only set up another iconic Giants moment in October, the back-to-back doubles from Brandon Crawford and Joe Panik that finally ended it.

You can beat the Giants in a lot of ways, but you’re not often going to win a battle of big postseason moments. It’s almost as if they’re assembled to be just good enough to survive long enough to punish teams for letting them linger, if that even makes sense.

“If we’re breathing, we’re still fighting,” Panik said.

That, more than anything, could be the Cubs’ undoing in this series. With the depth and power of their lineup, particularly compared to what the Giants are running out there, how are the Giants still breathing? For the Cubs to have essentially matched the Giants in offensive futility might be the most stunning part. The great maestro of October, Madison Bumgarner, lasted only five innings and, after he left the game, the Cubs managed just three more hits the next eight innings. Wasn’t the Giants’ bullpen supposed to be a disaster?

One of those hits happened to be a Kris Bryant home run that, if not for a gasoline advertisement nailed to the left-field wall, might have wound up in Gregor Blanco’s glove. Even that just turned into another example of the Giants’ unwillingness to go away. The reliever who gave up the home run, Sergio Romo, got six more outs after that.

“He didn’t let us lose the game,” Giants general manager Bobby Evans said. “He wouldn’t let us lose.”

For so much of Monday, it appeared the Giants’ even-year karma was petering out. Good fortune, like California sunshine, typically smiles down on the Giants at this time of year. It didn’t Monday. Replay officials declined to reverse a call at first base in the sixth inning that would have given the Giants their first leadoff baserunner all game. Javier Baez made a brilliant play up the middle, but his throw appeared to force Anthony Rizzo’s heel off the bag.

In the third inning, Hunter Pence hit a ball that seemed like it had a chance to tie the game or, at the very least, cut the Cubs’ lead to 3-2. Instead, Ben Zobrist ran it down in right-center field, roughly 400 feet from home plate.

According to Statcast, Pence’s ball left his bat at 108 mph and at a 26-degree launch angle. It was the first time all season when that combination didn’t result in a home run. In the fifth inning, Denard Span hit a ball to the same general area and it went for a triple. He scored on Brandon Belt’s sacrifice fly to make it 3-2 in the fifth.

Before all that, umpires declined to call Addison Russell out on strikes when he checked his swing against Bumgarner in the second inning. He then was hit by a Bumgarner pitch and wound up scoring in front of Jake Arrieta’s three-run home run. Bumgarner, partially because of that, had to throw 37 pitches in that inning.

If the Cubs can’t close this thing out in the next two games, they’ll keep coming back to two questions from Monday night’s game. How could they manage to lose a game when Bumgarner looked so human? And, how could they manage to lose a game in which the breaks finally went their way? If you’re not careful with them, the Giants are the kind of team that can leave a team muttering to itself for months -- if not years -- to come.