Fifteen pitches in to the moment he had waited for all his life, A’s pitcher James Kaprielian had the bases loaded and no one out.

Had the Boston Red Sox right where he wanted as it turned out.

Kaprielian escaped harrowing situations twice through five innings Wednesday in his major league starting debut as the A’s beat the Red Sox 4-1 at Fenway Park, their fourth win in five games.

“Minimizing damage is the name of this game,” Kaprielian said in a postgame video conference on the occasion of his first win.

After beating the A.L. East leaders twice in two nights, the A’s (23-15) can sweep the series Thursday before moving on to another three games in Minnesota. Boston fell to 22-16, stopped in its tracks by Kapreilian and relievers Burch Smith (two innings), Lou Trivino and Jake Diekman.

Diekman picked up his second save in two nights and fifth of the season.

Matt Olson homered for the A’s in the sixth inning his eighth of the season.

For Kaprielian, 27, it’s been a long odyssey that has included Tommy John surgery as well as twice having to rehab an injured shoulder. A former first-round draft pick of the New York Yankees, Kaprielian was the key player in the trade for pitcher Sonny Gray in 2017.

For all the time it took Kaprielian to get his first start, it took him almost no time to get into trouble.

A double by Marwin Gonzalez, a walk to Alex Verdugo and a single by J.D. Martinez loaded the bases with none out before Kaprielian struck out Xander Bogaerts and got Rafael Devers to pop to third.

Kaprielian then walked Christian Vazquez to force in a run before striking out Hunter Renfroe to retire the side having given up just the one run. It’s the only run Kaprielian would surrender, giving up four hits and walking three in a 95-pitch effort.

“Had some nerves, trying to do a little bit too much, yanking the fastball, and that really can’t happen,” Kaprielian said. “On the other side of that, keeping it at one, that’s a really big deal.”

A’s manager Bob Melvin complimented Kaprielian’s ability to escape the first-inning trouble in the most famous venue in baseball.

“You’ve got to give him a lot of credit for finding it in what can be a difficult environment and after a rough first inning,” Melvin said.

There was another jam of his own making in the fifth, when Kaprielian threw a would-be double play ball into center field but later recovered to make a flip to the plate to cut down one runner and end the fifth inning with two strikeouts.

“My journey to get to this point was an absolute struggle,” Kaprielian said. “There’s been ups and downs and times where it was great and times where it was bad. That’s kind of how the first inning was. At the same time, when my back’s against the wall you’ll never see any sort of quit out of me.”

If the spotlight was on Kaprielian, his father Doug got nearly as much attention the local broadcast.

“I couldn’t hear him during the game when I’m out there, but when I’m coming in off that top step, I can hear him,” Kaprielian said. “His voice is very distinct and I knew exactly what he was telling me. My dad’s all about competition . . . anyone in my family will tell you that.”

Besides his father, Kaprielian had an uncle and four friends fly into the game. He also felt the presence of his mother Barbara, who passed away in 2014 after a long bout with breast cancer.

“There are times when I’m struggling, and I don’t know if you guys ever catch it, but I take a pause and I look between the third base dugout and home plate,” Kaprielian said. “It’s the same spot my mom would always sit in my high school and college games. For me, that’s where I can kind of collect myself, gather my breath. It’s kind of my focal point.”

A’s give Rodriguez first loss

Boston starter Eduardo Rodriguez came in with a 5-0 record and while the A’s didn’t exactly wear him out, they got a run-scoring double in the second from catcher Sean Murphy. Then after Mitch Moreland walked and Elvis Andrus doubled him to third, the A’s got both runs home without getting the ball out of the infield.

Jed Lowrie’s slow chopper brought home Moreland, with Andrus taking third base. With Rodriguez going from a short windup, Andrus then made a break from third. Rodriguez aborted his motion for a balk, and Andrus scored.

On the previous pitch, Andrus scrambled back to third after catcher Christian Vazquez tried to pick him off.

“I wasn’t going to do it, but as soon as they try to get me at third base, you wake the beast up,” Andrus said. “I knew he was in the windup, and in those situations, try to break at the right moment.”

Murphy’s tag, Boston’s baserunning mistake

The only trouble among the A’s relievers came when Trivino had a one-out walk and then gave up a bouncing hustle double to Devers.

With runners at second and third, Vazquez hit a chopper to Lowrie at second. Lowrie got the out at first base, then first baseman Matt Olson caught Bogaerts trying to score form third, with Murphy making perfect swipe tag.

“It was a complete flip of the momentum at that point,” Melvin said.

Ramon Laureano ejected

A’s center fielder Ramon Laureano was ejected in the third inning after being called out on strikes by umpire Ryan Mills on a pitch that seemed well inside.