CHICAGO -- He was about as low as you can get for a major league baseball player, but Chicago Cubs catcher Miguel Montero's struggles never got him down to the point of mailing it in. Instead, he kept his head up and his attitude as positive as he could -- and he waited for his moment.

That moment came in a big way Saturday, as Montero became the third player ever to hit a postseason, pinch-hit grand slam, and he propelled the Cubs to an 8-4 victory over the Los Angeles Dodgers in Game 1 of the National League Championship Series. It was an instant classic featuring more managerial second-guessing than a regular season's worth.

“I’m not going to do any good to anybody being a cancer and being upset about it and being a cry baby,” Montero said of losing playing time. “I’m not going to be a cry baby. I’m going to keep my head up, and whenever they give me a chance, I’m going to take advantage of it.”

Take advantage of it he did. Montero hit an 0-2 slider -- the third one he saw in the short at-bat -- out to right field off Dodgers reliever Joe Blanton and sent the crowd of 42,376 into hysteria. According to ESPN Stats & Information, the 107 mph exit velocity was the fastest for a Montero home run since 2013.

“Obviously, as a kid, you always dream of the situations,” Montero said. “And that's what you live for. It's easy to hit a grand slam in the first inning when nobody is actually screaming at it, and this one is a lot more special because it's in front of this special crowd that we have, and you're always looking for that.”

Miguel Montero got only one at-bat in Game 1, but the 11-year veteran made it count. Patrick Gorski/Icon Sportswire

Two months ago, Montero wasn’t looking for home runs. He just wanted to be on the field. For the second consecutive season, he was fighting with two other catchers for at-bats while struggling to hit .200. Then the Cubs took even more away from him.

“In August, when they stopped catching me for [Jake] Arrieta,” Montero said. “For [David] Ross, it's easier. When he knows [Jon] Lester is pitching, he knows he’s in there. For me, if Arrieta is pitching and I’m not in there, when am I going to be in there? It was like roll the dice. Am I playing today? Am I playing tomorrow?”

As this was going on, Ross was being honored around baseball in the final days of his final season, and rookie Willson Contreras was garnering attention as the next great, young Cub. Remember: This is just a year removed from Montero, Ross and Welington Castillo vying for time behind the plate before the Cubs finally traded Castillo. Then Kyle Schwarber arrived in a big way, and Montero became the forgotten man.

“It wasn’t an easy transition,” he said. “It was hard, but I don’t expect it to be like that forever. ... I either play the game, or I’m going to be out of the game.”

That attitude paid off this September, when Montero hit .283 with a .353 on-base percentage. It was a far cry from his .154 June, and it gave the 33-year-old renewed hope that he would make the playoff roster. It helped when he hit the winning home run in the 10th inning of the Cubs' day-after-division-clinching victory in mid-September. After that game, he joked that he was happy he wasn’t released earlier in the season.

Fast-forward to Saturday night. You could feel the tension at Wrigley Field mounting. The Cubs had just blown an eighth-inning lead, and Dodgers manager Dave Roberts was doing everything he could to force Cubs counterpart Joe Maddon to pinch hit for closer Aroldis Chapman. The game was tied 3-3, and after two intentional walks sandwiched around a Javier Baez popup, Montero walked up to the plate.

“Just seems like he’s super locked in,” Kris Bryant said. “I thought he would come through with a hit -- maybe not a grand slam.”

Once the count got to 0-2, making contact was first and foremost on Montero's mind, but he did much more than that.

“He’s always studying pitchers,” reliever Pedro Strop said. “He’s really knowing if a guy is tipping [his pitches]. When he’s not playing, he’s always in the cage hitting and getting ready."

Montero did his part Saturday night, and he brought the Cubs within three games of their first World Series appearance since 1945.

“I feel like I have something left in the tank,” Montero said. “I had a bad year, but I might be the MVP of the World Series. I was kind of sarcastic, but the reality is you never know. Baseball is crazy. Anything can happen.

"No one is going to remember what I did in the regular season. You think people remember what I did three months ago or for the last six months? That’s the beauty of baseball.”