It's officially the grandest day in Major League Baseball history.

In the shadow of Jose Pujols ' 600th career home run, the first grand slam to ever bring a player into the 600-home-run club, Mike Zunino hit the seventh grand slam in the Majors on Saturday -- setting a new single-day Major League record.

The seven grand slams: Zunino with the historic seventh for the Mariners, Pujols for the Angels and No. 600, Kyle Schwarber for the Cubs, Matt Adams for the Braves, Ian Desmond for the Rockies, Travis Shaw for the Brewers and Chris Taylor for the Dodgers.

The previous record for grand slams in a single day was six, set on May 21, 2000. That day, the slams came off the bats of Garret Anderson, J.T. Snow, Brian Hunter, Jason Giambi, Shawn Green and Adrian Beltre , the only one of the group still playing in the big leagues today.

Pujols' home run was, of course, the most monumental. He became just the ninth player ever to hit 600 homers, joining Barry Bonds (765), Hank Aaron (755), Babe Ruth (714), Alexander Rodriguez (696), Willie Mays (660), Ken Griffey Jr. (630), Jim Thome (612) and Sammy Sosa (609). No. 600 for the Angels slugger was a majestic, high-arcing homer off former teammate Ervin Santana into the left-field seats at Angel Stadium.

Shortly afterward in Seattle, Zunino took Rays right-hander Alex Cobb deep with the bases loaded to give his team a 9-1 lead at Safeco Field. It was just his second home run of the season, but it's now etched into the record books.

Earlier in the day, Schwarber mashed his first career slam, and it was the decisive blow in the Cubs' 5-3 win over the rival Cardinals at Wrigley Field. With the Cubs trailing by two in the seventh inning, Schwarber crushed the first pitch he saw from Mike Leake a Statcast-projected 403 feet to the opposite field, changing the game with one swing.

"It was nice to come up in that spot and be able to help out," said Schwarber, who has struggled at the plate this season. "It's kind of a sigh of relief. I want to go up there and help my team, and for me to do that today was great."

The Brewers and Dodgers traded grand slams in Milwaukee, and in the end it was the Dodgers who came out on top, 10-8, thanks to Taylor. After Shaw hit a go-ahead grand slam in the seventh inning for the Brew Crew, the Dodgers trailed by three entering the ninth -- until Taylor, with two strikes against him, crushed a 430-foot go-ahead grand slam of his own off fill-in closer Carlos Torres , capping Los Angeles' come-from-behind win.

"When it got to two strikes, I just shortened up and wanted to put one in play in the outfield. He left one over the middle and I put a good swing on it," Taylor said. "That's the funny thing -- sometimes, the best swing is the two-strike swing, your batting-practice swing, when you don't have a tendency to do more, because that's when you get in trouble."

"You're up 8-4 in the eighth, that's a game we expect to win 10 out of 10 times," Shaw said. "This one [stings] a little bit."

Adams' solo home run in the 12th inning is what won the Braves their game against the Reds at Great American Ball Park on Saturday, but they wouldn't have even been in extras if not for his grand slam in the fifth. A 426-foot drive to center field, it was the first grand slam of his career and the first hit by a Brave since May 16, 2015.

"This is just a park where I see the ball well," Adams said after the game. "That helps too with the confidence. When you're in the box, you're feeling comfortable and knowing you're going to see the ball well. They've got a tough pitching staff. I was just trying to get a ball out over the plate and put some barrels on some balls."

With the Rockies facing the Padres in San Diego, Desmond's grand slam put the game out of reach. His 411-foot rip in the seventh inning was his third home run since coming to the Rockies, and also his third career grand slam. His last grand slam came on April 20, 2014 while he was still with the Nationals. Even though he's still getting back into the swing of things after missing most of April recovering from a left hand fracture, Desmond's slam was another step forward.

"I don't feel like I'm exactly at my best," Desmond said. "But it's all about keeping above water until you get hot. That's what I feel like I've been doing."