Boston Red Sox’s Sam Travis catches a pop out by New York Yankees’ Edwin Encarnacion during the sixth inning of a baseball game in Boston, Monday, Sept. 9, 2019. (AP Photo/Michael Dwyer)

BOSTON — The music blared in the clubhouse behind the door to manager Aaron Boone’s office — “New York, New York” was playing through the speakers, and a few voices could be heard joining in on the lyrics.

The New York Yankees had an extra reason to be happy after ending their longtime rivals’ run atop the AL East.

New York officially stopped Boston’s three-year reign as division champs, blanking the Red Sox 5-0 Monday night behind another big effort by James Paxton.

“Absolutely, it’s awesome,” Paxton said. “We feel really confident as a team right now and it feels great to knock those guys out.”

Hours after the defending World Series champion Red Sox parted ways with team president Dave Dombrowski, and right after former star David Ortiz returned to Fenway Park three months after being shot, they were shut out at home for the first time this season.

Boston dropped 18 ½ games behind the division-leading Yankees with 18 games left.

The Red Sox are still in playoff contention, but barely. They remained eight games behind the second wild-card spot.

Paxton (13-6) won his eighth straight start, allowing four hits in 6 2/3 innings, as the Yankees increased their lead to nine games over second-place Tampa Bay. New York is tied with Houston for the best record in the majors.

Austin Romine and Gio Urshela each hit solo homers for the Yankees, who took the final three of a four-game series and finished the season 14-5 against their longtime rivals. New York increased its club record to 270 homers, a night after setting the mark.

“It’s not about talent. We’re very talented, it just happened that over 19 games they were better than us,” Boston manager Alex Cora said.

Last year, the Red Sox clinched the East in Yankee Stadium, and also knocked them out of the playoffs there in the divisional round.

“We wanted to be in a position to win this division,” Boone said. “We know the Red Sox, defending world champs. We know how great they were a year ago. To play well against that team is satisfying. As far as who you knock out, we want to win a little more to shore up the division.”

Paxton struck out seven and walked three in setting a career best in victories.

Eduardo Rodríguez (17-6) gave up one run in six innings, striking out nine with five hits and a walk while throwing a season-high 117 pitches. He was 4-0 with a 1.03 ERA in his last four starts, and the Red Sox lost for just the second time (12-2) when he started at Fenway Park.

Romine sliced his homer down the right-field line past the Pesky Pole, making it 1-0 in the fifth.

New York broke it open by getting three runs off Darwinzon Hernandez in the seventh. Urshela led off with his homer into the Green Monster seats. DJ LeMahieu had an RBI double and scored on Gleyber Torres’ sacrifice fly.

Jackie Bradley Jr. had three hits for Boston.

CENTER OF ATTENTION

Ortiz threw out the first pitch, thanking the fans for their support after he was shot in the back in his native Dominican Republic.

In his first public appearance since June 9, when he was shot and seriously injured in a Santo Domingo nightclub, Ortiz walked out steady and strong to a cheering crowd before he threw the pitch to former teammate and catcher Jason Varitek.

“It’s amazing. It’s always good to see him back and in good spirits,” Bradley said. “He’s very thankful for all the prayers and doctors. He’s a special one to have, and we’re glad to have him as close to full strength.”

Yankees star Aaron Judge echoed the sentiment.

“To see him go walk on that field and throw a pitch out is fantastic,” Judge said. “I know the whole city loves him. The fans were going crazy. We were, too. I was just happy to see him back. It’s Big Papi.”

CENTER PLAY

Yankees CF Brett Gardner made a diving grab of Xander Bogaerts’ sixth-inning liner and Bradley had a leaping catch at the wall on Edwin Encarnación’s fly to end the seventh. Bradley also made a jumping snag of Luke Voit’s drive on the track, opening the eighth.

TRAINER’S ROOM

Yankees: Placed OF Mike Tauchman on the injured list (Grade 2 left calf strain; out 6-8 weeks). “Right now, I’m bummed out for him, but we’ve got to keep moving,” Boone said. … Boone doesn’t expect OF Giancarlo Stanton (right knee sprain) to play for Double-A Trenton before re-joining the Yankees. “Being down in Tampa, he’s able to face pitchers and able to rack up a lot of at-bats while he’s getting all the way back to physically being able to play games,” the manager said.

Red Sox: Cora said they are not planning yet to shut LHP David Price (cyst left wrist) down for the season. He hasn’t pitched since Sept. 1.

UP NEXT

Yankees: Haven’t announced a starter yet for their series opener at Detroit Tuesday. RHP Edwin Jackson (3-9, 9.16 ERA) is slated to go for the Tigers.

Red Sox: RHP Nathan Eovaldi (1-0, 5.77) is scheduled to start Tuesday when they open a three-game series Tuesday in Toronto. RHP T.J. Zeuch (0-0, 4.50) is in line to go for the Blue Jays.