BOSTON — Steve Pearce has hung around the American League East long enough to know Thursday night would not just be another baseball game.

“It will be epic,” said Pearce, often a visiting player to Fenway Park but now a resident of the Red Sox clubhouse for all of five weeks.

Pearce has played for every team in the division – including a 12-game stint with New York in 2012 – and knows what it means when the Yankees leave their pinstripes behind in Yankee Stadium, don their grays and walk into Fenway.

“I’m looking forward to it. I know it will be loud,” Pearce said.

Pearce proved to be the biggest noisemaker of all. Three big cracks of the bat had Fenway exploding with approval.

Pearce hit three home runs in his first five at-bats. His second was a three-run blast that ignited an eight-run fourth inning, giving Boston a 10-4 lead. His two-run shot in the sixth made it 14-5.

It was his first three-homer game.

Pearce, 35, spoke calmly before Thursday’s game but didn’t try to downplay the series.

“We’re not ignorant. We know it’s the Yankees,” he said. “Got to strap it on and be ready to play.”

While Pearce was talking pregame, Yankees slugger Aaron Judge ran around the infield. It wasn’t his customary home run trot, but drills to stay in shape. Judge wore shorts, and a brace around his broken right wrist.

Besides having no Judge and no Gary Sanchez (groin muscle strain), the Yankees put one starting pitcher (J.A. Happ) on the disabled list Thursday and dispatched another (Sonny Gray) to the bullpen.

“Our situation in very fluid,” Manager Aaron Boone said. He would prefer stable. New York is looking up from second place at the top-dog Red Sox.

“Obviously they’re a great team and having an amazing year,” Boone said.

But the Yankees began the series only four games behind Boston in the loss column. Boone knows what a sweep would do.

“We have a great opportunity this weekend,” he said.

Boone had CC Sabathia on the hill, the veteran who hasn’t lost to Boston in two years and was 6-0 with a 1.83 ERA in his last seven starts against Boston

Boston countered with Brian Johnson, substituting for ace Chris Sale, on the DL with a sore shoulder. Shortstop Xander Bogaerts was also out (sore hand) with Brock Holt filling in.

So what happens with the first batter? Holt can’t field a bouncer to his backhand. That error is followed by a single and then the first of two Didi Gregorius home runs. Boston trailed 3-0. Another home run (Aaron Hicks) and it was 4-0 in the second.

Johnson remained unperturbed. He allowed only one more run over the next three innings. He finished with 11 strikeouts over five innings, leaving with a 10-5 lead.

Johnson pitched to catcher Blake Swihart and Sea Dogs fans will remember that battery from 2014 – with Johnson going 10-2 with a 1.75 ERA.

In Johnson’s seven starts this year, he’s 2-1 with a 2.57 ERA.

“I like (Johnson) against anybody,” Red Sox Manager Alex Cora said earlier Thursday. “With what he has, he knows how to pitch. He’s obviously a starter. We’ve seen that throughout the season … he’s a lot more comfortable as a starter. He goes with his fastball in different spots in the zone and keeps them guessing.

“We feel good about him.”

Johnson should stay in the rotation – until Sale and Eduardo Rodriguez come back – and Drew Pomeranz sent to the bullpen. Johnson hasn’t done well as a reliever (5.10 ERA) and Pomeranz may be better in that role.

As for Sabathia, he didn’t get a decision Thursday, leaving after three innings with New York ahead 4-2. Boston made Sabathia work (72 pitches and four walks).

He exited early. The Yankees’ bullpen may be vaunted but the plan wasn’t to go to their “fourth-inning” guy. Poor Jonathan Holder. He faced seven Red Sox batters and didn’t record an out. His ERA zoomed from 2.06 to 3.50.

Boston bashed five doubles in the fourth inning, but it was the Pearce blast that got the Red Sox going.

Pearce was the first of three players obtained by Dave Dombrowski before the trade deadline. A right-handed hitting first baseman, he basically replaced Hanley Ramirez.

With Boston – before Thursday – Pearce was batting .333 with one homer in 17 games.

Dombrowski was criticized for not picking up a reliever at the deadline. Pearce, in his 12th major league season, seems to be a nice addition.

Kevin Thomas can be reached at 791-6411 or:

kthomas@pressherald.com

Twitter: @ClearTheBases