Kenley Jansen finishes off Yankees with 4-out save

BOSTON — On an electric Saturday night at Fenway Park, as fans of the Red Sox and Yankees tested the reach of their vocal chords to outdo each other, it was the home team that staved off its dangerous rivals in a satisfying 8-4 victory.

With the sell-out crowd of 36,673 buzzing from the first pitch, the Red Sox elicited deafening roars from their backers in a three-run first inning in which they bashed a trio of doubles (Jarren Duran, Tyler O’Neill and Jamie Westbrook) off the Green Monster against Yankees lefty Carlos Rodón.

Rafael Devers mashed a 112-mph two-run double to the gap in left-center with two outs in the second to make it 5-2 in favor of Boston.

While the standings show the Yankees with the best record in baseball (50-23) and the Red Sox just a game over .500 (36-35), the rivalry has a way of neutralizing factors like that.

“This is the best rivalry ever in the game. I’m grateful to have played in both rivalries. The Dodgers and the Giants, also, but you can’t compare this one,” said Red Sox closer Kenley Jansen. “This is so much different. It’s unbelievable. It was fun going out there, and the atmosphere was great.”

Jansen got so caught up in the action around him that he called down to the dugout and told manager Alex Cora he wanted the ball if things got sticky in the eighth inning. The big righty came through with his first four-out save of the season.

“The big man called in the middle of the eighth,” Cora said of Jansen. “He made the call, I didn’t make the call. He made it and said, ‘I’m in.’ So it was a fun game, and we’ve got a chance to win the series tomorrow.”

For a young and athletic Red Sox team that is gaining experience by the game, taking two out of three from the Yankees after they just did so against the equally loaded Phillies would make for a significant week.

“We’re young,” Cora said. “We’re going to lose some games, we’re going to win some games. It’s a good brand of baseball. It’s fun. The offense, when we’re clicking, it’s fun to watch. We’re going to put pressure on the opposition.”

If the early Boston highlights came from the offense, the bullpen staved off a possible Yankees onslaught in the mid-innings.

Some of the biggest outs of the game were the eight from Rule 5 Draft pick Justin Slaten. When the fearsome Aaron Judge walked to load the bases, pitching coach Andrew Bailey came out with some instructions on what to do against Alex Verdugo.

Slaten executed the plan with a first-pitch cutter that Verdugo pounded into the ground for a forceout. But there was still Giancarlo Stanton to deal with — he of the 17 homers this season and 419 for his career. Slaten punched him out with an 83.7 mph sweeper, leaving them loaded as the crowd roared with approval.

“Everybody was screaming on both sides. It’s just a really surreal feeling honestly,” Slaten said. “I had to kind of come in after I was done and just take a minute and kind of think like, ‘Wow, that’s the first time pitching in a game like that.’ All games matter, but it just felt like these last two and the one tomorrow just mean a little bit more.”

If this was new and exciting for Slaten, it was old hat for Jansen, but no less thrilling.

After the 36-year-old stranded two runners — including the potential tying run — to end the top of the eighth, the Red Sox gave him some insurance with two runs in the bottom of the inning.

Considering that Juan Soto, Judge and Verdugo were due up, that made life a little less stressful.

Jansen disposed of the dangerous trio on eight pitches to finish his 431st career save — two behind Baltimore’s Craig Kimbrel for fifth most all-time.

For all the talk about how Yankees fans dominated the atmosphere in New York’s 8-1 victory over Boston on Friday night, Red Sox Nation had a lot more to cheer about in the second game of the series.

“It was better today than yesterday,” Cora said. “They were very into the game. It is different, regardless of where the [Yankees] are at and where we’re. People care. And that’s the reason we played [on national TV] tonight and we’re playing tomorrow night. People watch. The last two days, you can feel it at Fenway.”