DETROIT -- Curtis Granderson will remember Saturday night for two reasons.
He got to meet his childhood hero, Ken Griffey Jr.
Then he got to beat him.
"I introduced myself to him before the game and we talked for a few minutes, just like two normal people," a star-struck Granderson said. "It's great to beat his team, but I know he's still a long way ahead of me. I just hope my career comes close to his."
The Tigers, who have won eight of nine, trailed 6-5 with two outs in the ninth, but Granderson brought the sellout crowd of 43,128 to its feet with his seventh homer.
"I'm learning how loud Tigers fans can be," Granderson said. "They aren't crazy like Chicago fans or New York fans, but they are loud."
The homer came off Reds closer David Weathers, who has blown three straight save chances.
"It stinks," he said. "I can't even say it was a mistake. I threw a fastball away and the guy hit it. It irritates you."
After Fernando Rodney (2-1) pitched a perfect 10th, Weathers (1-2) hit Carlos Guillen with a pitch with one out in the bottom half.
On a 3-1 count to Chris Shelton, Guillen stole second as Shelton swung and missed at what looked like ball four.
"You always try to do all the little things you can to win, and that includes running on that play," Leyland said. "Shelton swung at a bad pitch, and I think Guillen was out, but they dropped the throw."
Shelton walked on the next pitch, but Dmitri Young hit into a force at second, leaving runners on the corners for Craig Monroe.
Monroe hit a routine grounder into the hole at shortstop, but Lopez double-pumped before making a hurried throw that skipped past Rich Aurilia at first base. Guillen scored and was mobbed by his teammates at the plate.
"I was in an awkward position to get the ball out," Lopez said. "It was a tough play."
The Reds rallied for five runs in the seventh to erase a 5-1 deficit. With two outs and Cincinnati down 5-2, Griffey hit rookie Joel Zumaya's 100 mph fastball deep into the right-field stands for his 15th career slam.
"I wanted to go right after him," Zumaya said. "I've looked up to him for most of my life. I remember watching him when I was in Little League."
Griffey, who stayed in the training room after the game, has now homered in 42 parks, matching Sammy Sosa for second-most -- one behind Fred McGriff's record.
"Joel's not the first guy he's done that to," Leyland said. "He's a Hall of Famer who swells up in situations like that."
Adam Dunn led off the seventh with a homer against Mike Maroth, and Brandon Phillips singled with one out. That brought the hard-throwing Zumaya out of the bullpen. He allowed a single to pinch-hitter Javier Valentin, then struck out Ryan Freel before Lopez walked on a 3-2 pitch to bring Griffey to the plate.
"We came back and got a big homer from Junior to put us ahead," Reds manager Jerry Narron said. "When you battle back like that, that's tough to lose."
Eric Milton started for the Reds, allowing five runs and 10 hits in five innings.
Maroth gave up three runs in 6 1/3 innings and matched a season high with five strikeouts.
Detroit took a 2-0 lead in the first on RBI singles by Magglio Ordonez and Shelton, then got two more in the third after Phillips hit a solo homer in the top half.
Ivan Rodriguez led off with a double, Ordonez walked and Guillen loaded the bases with a bloop single.
Shelton made it 3-1 with a single to right and, after Young grounded into a force at the plate, Monroe's single gave the Tigers a three-run lead.
Ordonez homered in the fourth to make it 5-1, a lead that looked safe until Cincinnati's big seventh inning.
Griffey has not homered in St. Louis' new Busch Stadium. His 15th grand slam moved him into sole possession of 11th on the career list, one ahead of Gil Hodges, Mark McGwire and Mike Piazza. ... The Reds have three grand slams in 43 games this season. ... Milton was activated from the disabled list before the game, and Dave Williams was designated for assignment. Milton had been out since April 24 after knee surgery. ... The Tigers had won seven straight, their longest winning streak in 13 years, before losing Friday's series opener. ... Zumaya was the 344th pitcher to allow a homer to Griffey, but the first whose last name starts with a Z. ... It was the fourth-biggest crowd in Comerica Park history.