Mariners right-hander Chris Flexen had the game of his young career on Saturday afternoon at Fenway Park.

Flexen logged seven strong innings with a career-high seven strikeouts as Seattle defeated the Red Sox, 8-2, to win two of the first three in this four-game series and improve to 13-8 on the season.

Flexen pitched a beauty. He allowed four hits and his changeup was magnificent, while his fastball was clocked as high as 95 mph.

“I think he did a really good job of just mixing up his pitches -- just attacking different parts of the zone, working the cutter away from righties and into the lefties,” said Red Sox outfielder Alex Verdugo, who went 1-for-3 against Flexen. “The fastball was kind of riding to the righties up and away, and just did a good job of mixing his pitches. He pitched. You can’t get mad at that. He’s a guy that if you try to get a little big on him, you try to get a little anxious, it plays into his game.”

Flexen was also able to command his slider and curveball. His best inning was the third, when he struck out the side.  

“Each time I continue to learn, develop, continue to gain confidence, trust myself, sticking with the plan and keeping the same mindset every time I go out there, and that’s winning a ballgame,” Flexen said.

The Red Sox had runners in scoring position twice in the game and they took advantage of the situation in the seventh inning, when Marwin Gonzalez singled up the middle to score Rafael Devers.

“Flexen was awesome,”  teammate Kyle Seager said. “He was going right at guys. There was so much conviction. He was attacking guys. … He was on tonight and he was a lot of fun to play behind.”

Relievers Keynan Middleton and Will Vest contained the Red Sox the rest of the game and secured Flexen’s second victory of the season.

It was Seager who provided Flexen with most of the run support he would need. It’s safe to say that Seager is on fire. He went 3-for-5 with three RBIs and finished a home run shy of the cycle. In his last two games, Seager produced seven RBIs.

“I thought I would join in on the fun,” Seager said. “I’ve been doing a lot of work in the training room. The trainers have been taking care of me. [Hitting coach Tim Laker and assistant hitting coach Jarret DeHart] gave me some swing changes, kind of getting my hips working. It has been a process, but it always feels good to get hits and help the team.”

Seager’s big day started in the first inning when he singled to right field off Red Sox right-hander Nathan Eovaldi to score Ty France. An inning later, Seager tripled over the head of Verdugo in center, scoring Sam Haggerty and France for a 3-0 lead.

“Anytime these guys  jump on somebody to get the early lead, as a pitcher, it gives you a lot more confidence. It keeps you in attack mode,” Flexen said. “Obviously, Seager is a phenomenal player. He has done it for many years. He made some great plays at third base as well.”

In the fifth inning, Seager doubled over the head of Verdugo and later scored when shortstop Xander Bogaerts booted a ball hit by Taylor Trammell.

Seager struck out and popped out in his final two at-bats. He acknowledged that he was going for the cycle -- trying to hit a home run in those at-bats.

“It’s not something you go into the day thinking about. That was pretty cool for me. It was something a little bit different for me,” Seager said.