BOSTON -- Considering the success Astros outfielder George Springer has had against Red Sox starter Rick Porcello in his career, giving Springer a fourth plate appearance against the right-hander Friday night was quite risky.

Springer, a New England native, made the Red Sox pay by walloping Porcello’s 95th and final pitch over the wall in right-center field for a clutch two-out homer that sent the soaring Astros to their ninth consecutive win, 3-1, over the defending champions at Fenway Park.

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“I’ve seen a lot of balls here as a fan, as a kid, as a player, you hit it out there and it’s an out,” Springer said. “I was honestly happy I knew I was going to get Jake [Marisnick] to third right there with a fly ball and it went over the fence and I was obviously pretty excited about it.”

Springer’s American League-leading 17 homers are the most by an Astros player through the team’s first 45 games, and it was his fifth career go-ahead homer in the eighth inning or later.

“George hits a ball where, honestly, I haven’t seen a right-handed hitter hit the ball there in my time coming to Fenway,” Astros manager AJ Hinch said. “Impressive win and our pitching did really well to hang in there all the way to that last out, it was pretty exciting.”

Porcello carried a 1-0 lead into the eighth before giving up a leadoff double to Marisnick, setting the stage for Springer to play the hero. He crushed an 81 mph changeup and sailed it over the Red Sox bullpen.

“Huge at-bat by Jake getting to second base right there,” Springer said. “Honestly, trying to get him to third ... I was fortunate enough to hit a ball there pretty well and I’m happy to help us win.”

Springer entered the game 9-for-16 with two homers against Porcello before going 1-3 with a walk and a home run against him Friday. Red Sox manager Alex Cora said the decision to let Porcello face Springer a fourth time was a bad one.

“That was a bad one from the get go,” Cora said. “I mean, that’s the best lineup in baseball. He goes seven, and every pitch is high-leverage. He did his job, you know? The whole thing about one hitter and get him out, what’s the point? We have the best player in baseball right now with a man at second and no outs, that’s on me. That’s not on Rick. I just made a bad decision, put him in a bad spot, and we paid the price.”

Astros reliever Ryan Pressly worked a 1-2-3 eighth inning, setting a Major League record with his 39th consecutive scoreless outing (dating to last year). He made a terrific play for the final out, fielding a weak grounder from Rafael Devers and making an underhanded throw to first as he tumbled into foul territory.

Diaz to get MRI

Astros infielder Aledmys Díaz is set to undergo an MRI on Saturday morning after suffering discomfort in his left hamstring. Diaz beat out an infield single in the second inning and said he felt some pain in his hamstring on his final stride before crossing the base. He left the game after the half inning was over.

“It’s a little [worrying],” Diaz said. “Any time you have to get out of the game you worry, but I’m going to have an MRI in the morning and hopefully it’s nothing too bad.”

Diaz has started at second base in each of the last six games while José Altuve has been on the injured list with -- coincidentally -- a left hamstring strain. Tony Kemp took over at second base and made a terrific diving stop to retire Christian Vázquez to end the fourth and save a run.

“It’s the same thing that we’ve gone through with other players before,” Hinch said. “His hammy tightened up on the infield play and he’s day-to-day for now. We don’t really know if we’re going to have to do anything with him, but we’ll check him out again tomorrow and make a determination.”