HOUSTON -- A split decision is what the Red Sox left Minute Maid Park with on Saturday night. But it is a big one that puts swagger back in their step as this American League Championship Series heads back to Fenway Park.

Needing a quick bounce-back from a tight loss in Game 1, the Red Sox slammed the Astros early in Game 2 en route to a 9-5 victory.

And by slam, we are talking in literal terms. J.D. Martinez laced a grand slam to the opposite field in right with two outs in the top of the first. Rafael Devers mauled one down the line in right for another slam with one out in the second.

It was the first time in history a team hit two grand slams in one postseason game. And the fact it happened in the first two innings made life grand for the Red Sox and jarring for the Astros.

• 9 incredible facts from Boston's white-hot victory

The Red Sox, ever since Game 2 of the AL Division Series against the Rays, are the definition of a locked-in team at the plate.

"I think when we have this humble approach that we're not trying to do too much, then big things happen," said Red Sox manager Alex Cora. "And J.D., that was great to see [him] going the other way. Raffy, not trying to do too much and hitting the grand slam. It's a very good approach right now. We're not getting greedy. Like I said a few days ago, it's not about hitting 30 home runs or driving [in] 100 runs. It's about winning four games against the Astros. So now we got one, and now we go to Fenway."

With such good fortune on his side, hard-throwing Texan Nathan Eovaldi wasn't going to waste it. Boston's ace righty went 5 1/3 innings for the win, allowing five hits and three runs.

"To me, come playoff time, I want Nate on the mound, because he just seems to have it," Martinez said. "He has that dog in him where he comes out every time, and he makes it really, really hard on those hitters."

The Red Sox have won all three of Eovaldi's starts this postseason and all five he's made for them in total. There aren't many pitchers you'd rather hand the ball to this time of year.

"He's been a horse for us, he's been amazing and he went out there and did an amazing job," Cora said.

Just as there aren't many hitters a team would like to face less right now than Kiké Hernández, who has performed with an outrageous level of success in these playoffs. Boston's suddenly unstoppable spark plug went deep again as part of a two-hit day.

His five homers this postseason tie with Todd Walker (2003) and David Ortiz ('04, '13) for the all-time club record.

But here's the most impressive part: Hernández has the most hits (15), extra-base hits (nine) and total bases (34) by any player in a five-game span in postseason history. If you're curious about Red Sox history, Hernández is now the record-holder in that category for any five-game span, surpassing beloved 2004 "Idiot" Kevin Millar (32 extra bases from July 21-25, 2004).

And perhaps nobody should have been surprised Boston bounced back in such resounding fashion. Under Cora, the Red Sox are 5-0 following losses in the postseason, meaning they've never lost back-to-back games in October under his leadership.

"It's huge," Martinez said. "We came here, we were like, 'We've got to split. That's all we have to do.' Obviously, we would love to win both of them. I think that's a little wishful thinking against a team like this. So, to get the split here and to go back home with our fans, who have been unreal the entire postseason, it will be fun. It's exactly what we wanted."

Though these Red Sox came into the season and the playoffs as underdogs, this is starting to take on the feel of one of those Octobers that turns special for Boston.

Cora's team is 5-2 this postseason. Cora is 16-5 (.762 winning percentage) as a manager in the playoffs. That winning percentage is the best for any manager with at least 21 games under his belt, and it ties Earl Weaver for the best 21-game start to a postseason career for any skipper.

"For me, I think it's just the energy," said Martinez. "Alex brings energy into the clubhouse. You hear him always yelling from the dugout. He is yelling after every pitch, so I think it kind of just resonates with everybody, and everybody feels that energy and that presence."

Perhaps by losing Game 1, Boston had the Astros just where they wanted them. The last three times the Red Sox lost Game 1 of the ALCS prior to this (2004, '13, '18), they've gone on to win the World Series.

After an off-day on Sunday, the Sox will try to ride their momentum into Game 3 at what will be a rocking Fenway Park. Boston is 3-0 at home so far this October.

"It feels good," Devers said. "Obviously, like I said before, Houston is a really good team, and being able to split here and now we're able to go back home to Fenway where we're comfortable and we know how we can play over there, this is really good for us."