In the bottom of the third inning, the shortstop hit a mammoth shot against righty Jason Hammel that soared near the top of the light tower above the Green Monster and on to Lansdowne Street to give the Red Sox a 6-3 lead in a game they trailed 3-0 in the first.
"I think we've been taking a lot of good pitches with guys on base, especially bases loaded, and then we're getting some good swings in hitters' counts," said Bogaerts. "I mean, I'm in a 3-2 count right there. I don't think he really wants to walk me after he already walked two guys, so I think we've been really selective and waited for a good pitch to hit."
Amazingly, the surge in slams comes on the heels of the 2017 Red Sox not hitting any grand slams.
"I didn't hit a grand slam in my career, so it's not because of me," quipped manager Alex Cora.
But the turnaround -- not just with grand slams but with overall power -- has not come by accident. The seeds were planted by the drills hitting coach Tim Hyers ran throughout Spring Training.
"When I talk about those situation drills Timmy had in Spring Training, there were a few that were [designed] to hit the ball in the air, avoid the ground ball so you don't hit into a double play and avoid two easy outs," said Cora. "So I guess they're trying to get under it and hit the ball in the air."
The drive by Bogaerts had an exit velocity of 110 mph, the hardest-hit homer by Bogaerts since Statcast™ started in 2015. The third homer of the season by Bogaerts traveled a projected distance of 430 feet.
"Honestly, they put some really good at-bats together there, stretched the pitch count there," Hammel said. "Xander put a good swing on a pitch. It wasn't a very well-executed pitch, but I wasn't getting very many swings on the slider, which was surprising. Any time you can get four runs on one swing, you can do some damage. That was pretty much the story."
Mookie Betts, J.D. Martinez, Rafael Devers and Mitch Moreland are the other players to hit grand slams for the 21-7 Red Sox through the first 28 games of the season.
Playing in his third game since returning from the disabled list, Bogaerts (3-for-5) looks as locked in as he was before the injury.
"He been pretty amazing for us all year," said Moreland. "Obviously with the injury, not knowing what to expect coming back, but he's picked up right where he left off. That's a huge shot in the arm for us, getting him back out there. I mean, obviously tonight, coming up with the grand slam, and he had three hits. It's a nice night."
The first slam for Boston in 10 days was well-timed. For this was not a pretty night for Red Sox lefty Eduardo Rodriguez, who threw 35 pitches in the first, walked three and hit a batter to pin his team in a 3-0 hole before they took a swing.
Moreland (3-for-4, double, homer, three runs, two RBIs) belted a solo homer in the second to give the Red Sox some life.
Even after Bogaerts gave Boston the 6-3 lead with the slam, Rodriguez couldn't last the five innings necessary to get the win. He gave up five hits and five runs over four innings, walking three and striking out six.
Hector Velazquez provided a couple of big bridge innings (one hit, no runs, three strikeouts) to earn the win, and the offense continued to add on.
"Good at-bats all around," said Cora. "I do feel we were a little bit more aggressive from pitch one, regardless of the score. [Leadoff man] Andrew [Benintendi] was ready to hit from the get-go and we weren't as passive as the last few days. When you do that and start hunting strikes and pitches in the zone, good things are going to happen. We didn't expand. We made him throw the ball over the plate and put good swings on it."
SOUND SMART Barrel roll: Bogaerts had two barrels in this one to give him eight for the season. Last year, he had only six all season. A barrel is a batted ball with an ideal combination of exit velocity and launch angle.
HE SAID IT "I don't look at it as roles. We've got a group of 25 guys in here and every one of them are going to do something. Their role is going to be to help us win. That's the way we look at it. That's the way I look at it. That's the only role I've got, is to go out and try help the team win. If we win the big one at the end, then I think my role is looking pretty good." -- Moreland, when asked about staying sharp despite playing less this year
UP NEXT The Red Sox expect to get right fielder Mookie Betts back in the lineup on Tuesday. Betts didn't start the past two games due to tightness in his right hamstring. Ace Chris Sale makes the start for Boston, while Kansas City counters with Jakob Junis. First pitch is scheduled for 7:10 p.m. ET.