LOS ANGELES — The Cubs burst from the starting gate this season and never looked back, embarking on a bruising conquest of the National League. They won 103 games, outscored opponents by 259 runs, and spent all but one day splashed in the sunshine of first place.

But that charmed existence doesn’t matter now, because if the Cubs hope to end their 107-year championship drought, they must show that they can get up from a shot to the chin. The blow was delivered by the Dodgers, whose 6-0 victory Tuesday night left the Cubs a 2-to-1 deficit in this best-of-seven National League Championship Series.

For the first time in the playoffs, the Cubs must play from behind to advance, all while hoping that an offense that has been shut out in consecutive games can somehow spring to life. It is a new level of pressure for a group that has been sheltered from it all year long.

“Nobody said it was going to be easy,” said Cubs third baseman Kris Bryant, one of the few on his team not mired in an October slump. “It isn’t easy to win a World Series.”

Yasmani Grandal and Justin Turner each homered for the Dodgers. Corey Seager had three hits, including an RBI single to give his team the lead. And Kenley Jansen recorded the final four outs, continuing a postseason in which he has thrived when freed from the one-inning confines of what’s expected from a closer.

But it was a former Long Island Duck who did the most to ease the Dodgers into the driver’s seat. Lefthander Rich Hill, whose career revival began with the Ducks, tossed six shutout innings against a Cubs lineup that has been forced to relive a nightmare.

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A season ago, the Cubs were swept from the NLCS, shut down by the Mets’ pitching. With that memory in mind, manager Joe Maddon reshuffled his lineup before Game 3. None of Maddon’s maneuvers worked. The Cubs are hitting .185/.242/.335 in the postseason. Their .577 OPS is the lowest of the teams still standing.

“We did attempt to shake it up a little bit today and obviously didn’t play very well,” Maddon said. “But listen, I’ve got a lot of faith in our guys.”

Anthony Rizzo, dropped one spot down into the cleanup spot, went 1-for-3 with a walk. His only hit came on a broken-bat single with the game already out of hand in the ninth. He is 2-for-26 in seven postseason games.

Ben Zobrist, moved up to the third spot, was 0-for-4. He is 4-for-26 in the playoffs. Shortstop Addison Russell, moved to the seventh spot, went 0-for-2 before he was pinch hit for in the seventh inning. Russell is 1-for-24 in October.

Hill thrived against a lineup that has lost its way, using a flurry of curveballs to handcuff the Cubs, though at the start it was not easy. He needed 30 pitches to escape from a sloppy second inning, in which he and batterymate Grandal appeared out of sorts.

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After putting up a zero, Hill retreated to the Dodgers dugout and slammed his glove on the bench. But after needing another 25 pitches to navigate the third, the Cubs failed to punish a pitcher on the ropes. They suffered the consequences. Hill found a rhythm.

“His preparedness, his guts, really kept those guys at bay,” Dodgers manager Dave Roberts said. “Changing speeds, pitching off the breaking ball, mixing in the fastball, he kept them off balance all night.”

Suddenly, every curveball caught the corners. He threw them over the top, sending them to the plate diving toward the dirt. He slung them in sidearmed, a particularly nasty trick against lefties, who flailed at frisbees that darted out of the zone. As the game dragged on, those benders made Hill’s other offerings seem more lively.

“Curveball command definitely got better as the game went on,” said Hill, who didn’t last past the third inning of his last outing, Game 5 of the NLDS.

Meanwhile, Cubs righty Jake Arrieta allowed four runs and six hits in five-plus innings, nowhere near good enough to cover up a Cubs offense that has stalled as it did against the Mets.

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“New team, new season,” Bryant said. “I haven’t really thought of last year at all. This is a very different situation, too. I felt like last year, the pitching just beat us. And I feel like right now, we’ve had some chances.”

Yet, the results have been no different. The Cubs hit .162 in a four-game sweep against the Mets in last year’s NLCS. Through three games this year, they are hitting only .161. But the Cubs downplayed the suggestion of a repeat, and they bristled at the notion of encountering adversity for the first time.

“I can’t get so dramatic about it,” said Maddon, who has long scoffed at the idea of the Cubs’ painful history becoming another burden to carry.

While the Cubs compiled 103 wins, the most in the big leagues, Bryant said they did so only by overcoming tough times within individual games. It is experience that will come into play now.

As for the perception of facing pressure for the first time this season, Bryant said it “couldn’t be further from the truth.”

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“We’re only down 2 to 1,” Bryant said, as he tried to project calm. “It’s not like last year at this time when we were down three.”