NEW YORK -- While players on the Yankees bench gaped at Gary Sanchez's one-handed homer, manager Aaron Boone was already thinking about his next relief pitcher.

"Once we got the lead," he said, "we felt like we had a chance to really roll out our guys."

No surprise -- Boone's bullpen big guns delivered again.

Sanchez hit a tiebreaking, two-run homer in the fifth inning, Aroldis Chapman escaped trouble in the ninth and New York's `pen held tight to beat the Boston Red Sox 5-3 Saturday night.

After starter Domingo German was chased early, six Yankees relievers combined for 5 1/3 scoreless innings to lock down another victory over the rival Red Sox -- New York is 4-0 to start the season series, a first since 2012.

"We've done it a lot of different ways," Boone said. "We've won games in a lot of different ways. Tonight was a battle. It was a heavyweight fight."

Chapman walked Mookie Betts and allowed a single to Andrew Benintendi leading off the ninth, but J.D. Martinez hit a double-play grounder and Rafael Devers rolled the last out to first. Chapman got his 17th save in 18 tries, closing out a game where Chad Green (1-2) and Adam Ottavino also stranded runners with timely strikeouts. The bullpen also pitched four shutout innings in a 4-1 win Friday and has covered 24 1/3 consecutive scoreless innings.

The Yankees have won 15 of 18 and clinched their ninth straight series victory, a first for the franchise since 1998.

Boston went 2 for 14 with runners in scoring position, including seven strikeouts. The Red Sox tied a season high with 14 strikeouts and matched a season most with their fourth straight loss.

"We didn't do too much with men in scoring position," manager Alex Cora said. "We've been talking about this for like a week. There's always traffic and all that, but we're not getting that big hit."

Xander Bogaerts homered and had three hits for the Red Sox, who fell 9 1/2 games behind New York for the AL East lead. It's Boston's biggest deficit in the division since finishing 15 games out in 2015.

"We're not closing the gap," starter Rick Porcello said. "We're making it bigger. It's tough."

Sanchez threw his hands at Porcello's 2-2 slider well outside the strike zone and poked it an estimated 403 feet to right-center. It was Sanchez's 18th homer, matching his total from an injury-spoiled 2018. He was in a five-way tie for the AL home run lead before connecting.

"It was kind of a one-handed swing," fellow slugger Luke Voit said. "I don't know how he did it."

"Not many guys are capable of doing that," Brett Gardner said.

Right-hander Luis Cessa was warming for New York when Sanchez delivered his go-ahead drive. Boone quickly got Tommy Kahnle loose instead, setting up the back of the bullpen for another shutdown show.

DJ LeMahieu's two-run single put New York ahead 3-1 in the second, but Boston tied it in the fourth on Bogaerts' leadoff homer and Sandy Leon's second RBI single of the game.

"Today, Sandy was the only one that got hits with men in scoring position," Cora said. "We struck out too much today. Sometimes, it's credit to them. Sometimes, it's just we're expanding the zone."

Leon was 3 for 3 before Cora replaced him with pinch-hitter Christian Vazquez with a runner on in the eighth. Vazquez hit into an inning-ending double play.

Porcello (4-5) entered with a hot hand, but left after allowing five runs in 4 2/3 innings.

German allowed three runs in 3 2/3 innings, failing to qualify for what would have been his major league-leading 10th victory. He struck out eight but gave up six hits and two walks.

"I think they wore him down," Boone said. "They made it difficult for him."

Yankees DH Kendrys Morales ended a 1-for-19 skid with three hits. Voit also had three hits.

BACK ON TOP

Before the game, Cora informed Betts that he would be hitting leadoff for the rest of the season. Betts batted first throughout his MVP 2018 season, but Cora opened this year experimenting with Benintendi in the top spot with Betts at No. 2. The duo was 2 for 9 with a walk and three strikeouts combined.

TRAINER'S ROOM

Red Sox: Boston placed World Series MVP Steve Pearce on the 10-day IL with a low back strain. 1B/OF Sam Travis was recalled from Triple-A Pawtucket. ... RHP Nathan Eovaldi is set for a second simulated game Tuesday as he works back after having a loose body removed from his right elbow April 23. He threw 22 pitches in a sim game Friday.

Yankees: OF Clint Frazier was pulled an inning after being hit by a pitch in the left elbow. X-rays came back negative, and he'll be re-evaluated Sunday. ... Boone said SS Didi Gregorius could join New York for its series at Cleveland from June 7-9. Gregorius is with Triple-A Scranton/Wilkes-Barre on a rehab assignment following Tommy John surgery last fall.

UP NEXT

Boston's David Price (2-2) and New York's CC Sabathia (3-1) face off in a showdown of Cy Young Award-winning left-handers.

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