NEW YORK (AP) – Cam Schlittler’s key to putting Boston Red Sox bats to sleep was his own slumber.

Making only his 15th major league start, Schlittler struck out 12 in eight dominant innings Thursday night as the New York Yankees blanked Boston 4-0 to win their AL Wild Card Series in a deciding third game.

Overpowering hitters with 100 mph heat in a winner-take-all elimination game, the 24-year-old rookie became the first pitcher in postseason history to throw at least eight shutout innings with 12 or more strikeouts and no walks.

Against the archrival Red Sox, no less, the team he grew up rooting for in Massachusetts.

“A star is born tonight,” manager Aaron Boone proclaimed after his Yankees advanced to a Division Series matchup with Toronto.

Schlittler prepared for the big moment by speaking Wednesday with Yankees great Andy Pettitte, a five-time World Series champion and winner of a record 19 postseason games.

“I got really good sleep last night. I wasn´t too worried about it,” Schlittler said. “I woke up and I was locked in, so I knew exactly what I needed to do and go out there, especially against my hometown team. So as I told Andy yesterday, I wasn´t going to let them beat me. So I was just overconfident in that fact, making sure I wasn´t getting too carried away with it.”

The 6-foot-6 Schlittler started the season at Double-A Somerset, was promoted to Triple-A Scranton/Wilkes-Barre on June 3 and debuted in the majors July 9 after Clarke Schmidt injured his elbow.

Schlittler grew up a Red Sox fan in Walpole, Massachusetts, but has said several times he wanted to play for the Yankees. He had faced Boston only once before, as a freshman at Northeastern in a 2020 spring training exhibition.

He outpitched Connelly Early, a 23-year-old left-hander who debuted on Sept. 9 and became Boston´s youngest postseason starting pitcher since 21-year-old Babe Ruth in 1916. Schlittler threw 11 pitches 100 mph or faster – including six in the first inning, one more than all Yankees pitchers had combined for previously since pitch tracking started in 2008.

“He is not afraid. He expects this,” Boone said.

Schlitter’s strikeouts were two more than any other Yankees pitcher had in his postseason debut. He allowed just five singles and threw 75 of 107 pitches for strikes, starting 22 of 29 batters with strikes and topping out at 100.8 mph.

“Impressive, but he´s been our secret weapon ever since he got called up,” Yankees captain Aaron Judge said. “No moment is too big for him.”

His cap pulled low, just like Pettitte, Schlittler got 18 swings and misses – 11 on fastballs.

“Electric stuff,” said Boston’s Alex Bregman, a two-time World Series champion.

New York took the lead with a four-run fourth set up when Cody Bellinger’s soft fly dropped in front of center fielder Ceddanne Rafaela. Amed Rosario and Anthony Volpe each had an RBI single before Austin Wells hit a potential double-play grounder that glanced off first baseman Nathaniel Lowe’s glove and into shallow right field as two runs scored on the error.

Schlittler kept his head bowed when he walked to the dugout after his final out in the eighth, showing only the slightest emotion with a small fist pump and tip of his cap to the capacity crowd of 48,833 at Yankee Stadium.

“As pressure-packed a game as I have ever been in, as a player, manager, going into the World Series, that´s clinching to go into a World Series, just because the context in my brain of what I think our team is,” Boone said.

Schlittler hadn’t reached double digits in strikeouts since pitching for Northeastern against James Madison on April 17, 2022, three months before the Yankees made him a seventh-round draft pick and signed him for a $205,000 bonus.

“I think it´s a testament to him and his work ethic and his determination and his mindset. He comes from a great background. His family and coaches I think gave him a lot of positive mentorship that allowed him to be the best he could be,” Yankees northeast amateur scout Matt Hyde said. “I kept watching him coming back to the dugout and he was keeping his head down. He was going about his business.”

Schlittler has a WHOOP device affixed to his left shoulder that sends measurements to an app on his phone, tracking heartbeat, strain, levels of sleep and recovery. The company that makes it is based in Kenmore Square, down the block from Fenway Park in Boston.

“I got 96% recovery two nights ago and then I got like 93 last night,” he said. “I was really comfortable, last night going to bed and being confident in myself.”