That's a shooting pain that will leave the Reds throbbing for a little while, at least until Tuesday evening, when the two teams play again.
"It's devastating when you see the ball go over the fence," Reds manager Dusty Baker said of the homer that did his team in.
In the seventh, Reds starter Mike Leake allowed leadoff batter David Freese to start the rally with a single to left field, and Carlos Beltran delivered a one-out, pinch-hit double to left-center field. Third-base coach Jose Oquendo conservatively held Freese from scoring, and with the Cardinals entering leading the Majors with a .327 on-base percentage, it became clear why.
"This one hurts a little bit," said Leake, who was charged with five runs over 6 1/3 innings. "Especially when you get one pitch away from coming out of there that inning with a lead and locking it down with our bullpen. We had a chance and couldn't take advantage of it."
Lefty Manny Parra replaced Leake and issued a walk to lefty-hitting Matt Carpenter that loaded the bases. Jon Jay followed with a routine slow grounder to first base. Joey Votto touched the bag and headed for the dugout thinking he had three outs. Although a bad miscue on Votto's part, one which he acknowledged postgame, it was unlikely there was any chance at an inning-ending double play.
Hoover replaced Parra to face Matt Holliday, who worked a 3-2 count before drawing a walk on a very close pitch to load the bases.
"That last pitch was close," Hoover said. "I think it could have went either way. Unfortunately, I walked him."
The next pitch was even more unfortunate.
On a first-pitch fastball, Craig hit an opposite-field drive to right field for the grand slam. He is now 6-for-7 with 15 RBIs in two-out, bases-loaded situations this season and has a Major League-best .452 average with runners in scoring position overall.
"It's huge," Craig said of the win. "There's a decent amount of games left, but in the grand scheme of things, not really. It's getting to crunch time. Our schedule has been extremely tough, and it doesn't get any easier. We needed to win this game. It's the start of a big series."
For Hoover, it's been a stunning about-face after he went 26 1/3 innings without allowing a run. He's now allowed two grand slams in one week, with D-backs slugger Paul Goldschmidt's Tuesday grand slam being the streak ender.
"I was trying to go away," Hoover said. "I know he's a good hitter. I know he's a really good hitter with the bases loaded. I didn't want to come in there with the first pitch because I didn't want to risk hitting him. I let it go that way. He got it. I left it a little bit over the plate."
Jay Bruce's solo homer to left field in the eighth inning against Seth Maness was as much as the Reds could muster in response. Cincinnati fell 3 1/2 games behind the Cardinals, who took over sole possession of first place in the National League Central by a half-game over the idle Pirates.
The Reds are 4-9 vs. the Cardinals this season and have won three series out of 29 at St. Louis since 2003, and none since 2011. But the bad mojo seemed poised to turn in the early going against lefty Tyler Lyons.
During a nine-batter, four-run top of the second inning, Zack Cozart, who entered 4-for-39 lifetime at Busch Stadium, hit a two-run triple through the gap in right-center field. With two outs, Todd Frazier -- who was 1-for-40 this season vs. the Cardinals entering the at-bat -- sent a two-run triple through the gap in left-center field for a 4-0 Reds lead.
It wouldn't be enough. Three of the big Reds hitters -- Shin-Soo Choo, Votto and Brandon Phillips -- went a combined 0-for-11. Lyons retired his final 10 batters in a row and exited following five innings.
In the bottom of the third inning, with one out, Leake gave up a three-run homer to Holliday, who tattooed his drive to the left-field upper deck.
"We know a lot of times it wouldn't be enough here in this ballpark," Baker said. "We had some opportunities to get some more and let him off the hook. Their bullpen shut us down."
It was the first of seven games vs. the Cardinals out of their next 10. Even as this loss burns, the Reds have to make sure they don't stay down.
"It's because we're getting down to crunch time and every series is important," Hoover said. "I hate giving up the lead vs. any team because every win is important. If you go back and lose the division by one game, you can go back through the year and any game is that important game. So that's how I treat every game. It just happened to be against the Cardinals."