CHICAGO — They do not play in Philadelphia and they do not profile as scrappy underdogs. So on Sunday night, just before the Cubs took the field and tried to save their season, it all seemed forced when the ballpark’s loudspeakers blasted “Going the Distance” from “Rocky.”

But deep in the guts of Wrigley Field, out of sight from the nervous-wreck Cubs fans in the crowd of 41,711 who had settled in and braced for the worst, first baseman Anthony Rizzo demanded that every television in the Cubs’ clubhouse show Rocky I, Rocky II, Rocky III and Rocky IV, all at the same time.

And when this wasn’t enough to ease the tension before facing elimination, catcher David Ross said Rizzo was spotted “running around, jumping around, half-naked, doing boxing moves.”

“I wanted to let everyone know that we’re planning to go the distance,” Rizzo said, quoting one of the film’s iconic lines, shortly after the Cubs forced a sixth game in this World Series. “Obviously, there’s a lot more that goes into that. But we’ve bought in. And we believe in it.”

For the first time this season, Rizzo walked up to music from “Rocky,” then used the aftermath of a fourth-inning double to drive home his point. Upon reaching second, he popped out of his slide, crouched into a boxing stance and fired a three-punch combination into the crisp night air. After the natural southpaw’s left-right-left flurry, he looked to his dugout and screamed “Let’s go!”

In that moment, Rizzo personified a team that became more emboldened after a 3-2 victory over the Indians, one that ensured that the Cubs will play in Cleveland on Tuesday night. At no point this season had the Cubs been more vulnerable to unraveling under the pressure, but they further assured themselves that there’s still time to slug their way out of a corner.

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“You keep adding to your resume of things you have to deal with mentally, what you go through, and how you prepare and go about your business on the field,” Ross said. “The more that gets thrown on these guys’ shoulders . . . They seem to answer the bell.”

The Cubs trafficked in slogans throughout their 103-win season, using motivational messages to combat the negativity that comes with a championship drought that stretches to 1908.

Manager Joe Maddon speaks of “Embracing The Target,” and it’s easy to spot shirts here that read “Make Someday Today” or “Try Not To Suck.”

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“We have a T-shirt for everything,” Kris Bryant joked earlier this postseason.

But the Cubs often find comfort in their clichés, inoculating themselves with soothing words before facing an adversary that is unique to them. For all of Wrigley Field’s beauty and charm, it still is a place that until Sunday night had not hosted a win by the Cubs in a World Series game since 1945.

Here, doom and gloom are passed like heirlooms from one generation to the next, and all it takes is for one bad thing to happen to feel its full force. With one swing, Jose Ramirez turned the Friendly Confines into a mausoleum Sunday night, blasting a second-inning homer off Cubs starter Jon Lester to put the Indians ahead 1-0.

“There was just a lot of emotion,” leftfielder Ben Zobrist said. “When they scored the first run of the game, too, it was kind of like the air went out of the stadium a little bit. People, you could tell that there was a little bit of hanging of the heads. But we needed to answer back. We had to answer back to get them back into the game.”

The answer came when Bryant socked a solo shot in the fourth, the first blow in a three-run rally that revived Wrigley. Now the Cubs had a lead to protect, a responsibility that fell to fireballing closer Aroldis Chapman. He entered with the Cubs up a run with one out in the seventh. Never before had he recorded the final eight outs of a game.

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“High anxiety,” Rizzo said. “Just every pitch, here in Chicago, with the crowd, you can just feel the nervous energy. It was awesome. It was really awesome for all of us to experience that.”

As Chapman smothered the Indians with 100-mph fastballs, the rest of the Cubs sweated through the most excruciating 42 pitches of the season.

Kyle Schwarber’s bad left knee relegated him to pinch-hitting duty the last three games, so he was confined to the batting cages, his head in his hands, muttering “come on, we can get out of it, I know we can” to himself as Chapman pushed the Cubs closer to another day.

Rizzo, 27, cracked jokes about Ross, 39, wondering if the strain of such a game could be good for someone of advanced age.

“I kept running in here between innings telling the security guard there that my heart can’t take any more of this, you know?” said Ross, who will retire at season’s end.

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But by the end of the night, streamers sat on the warning track, the remnants of the celebration that Chapman unleashed. Atop the iconic centerfield scoreboard flew a white flag emblazoned with a blue W, the North Side’s unofficial banner of victory.

Only five of 34 teams have rallied from a 3-1 deficit to win a best-of-seven World Series. It hasn’t happened since 1985, when the Royals beat the Cardinals. It hasn’t happened on the road since 1979, when the Pirates stunned the Orioles.

“Why not us?” Bryant said.

Though they still face long odds, the Cubs sent the proceedings back to Cleveland, where they maintain at least a puncher’s chance of winning this World Series.

Said Rizzo: “We’ve got to go the distance.”