With one swing, the Red Sox slugger turned everything upside-down.
Ortiz's grand slam erased an eighth-inning deficit and ended Detroit's unprecedented run of pitching dominance, and Jonny Gomes scampered around the bases with the game-winning run in the ninth Sunday night to give Boston a 6-5 victory over Detroit and knot the AL Championship Series at one game apiece.
"That's what he does. He's an amazing hitter," said Max Scherzer, who took a no-hitter and a 5-0 lead into the sixth inning but could only watch as the Detroit relievers blew it. "He's an amazing postseason hitter. He's clutch. Any given moment, a swing of the bat he can always take you deep."
One night after Anibal Sanchez and four relievers came within two outs of the first combined postseason no-hitter in baseball history, Scherzer struck out 13 and held Boston hitless for 5 2/3 innings. But the Red Sox loaded the bases against three relievers in the eighth and then closer Joaquin Benoit came in to face Ortiz.
The Red Sox designated hitter lined the first pitch into the glove of the Red Sox bullpen catcher. Hunter went down hard and came out only after his teammates had waved for the Detroit medical staff to come out and help him.
"I jumped up. I thought I had a bead on it," said Hunter, who came up in the Minnesota Twins organization with Ortiz and remains friends with the Red Sox slugger. "Next thing, I know I'm falling over the fence."
The fans waited until the trainers verified that Hunter was OK to start chanting, "Papi!" and call Ortiz out of the dugout for a curtain call. It was the first career postseason grand slam for a star of the 2004 playoff run that ended in Boston's first World Series title in 86 years.
"The guy's an actor at work," Red Sox outfielder Shane Victorino said. "It's fun to watch. It's great to see. He's always upbeat and always positive. He always likes to go up and swing the bat. That's what he always wants to do."
Koji Uehara pitched a perfect ninth for the win.
Rick Porcello gave up a leadoff infield single that left Gomes at second when shortstop Jose Iglesias threw the ball into the Boston dugout. Jarrod Saltalamacchia hit a foul popup that glanced off first baseman Prince Fielder's glove when he got tangled up with a fan.
Gomes moved to third on a wild pitch, and then Saltalamacchia hit one through the drawn-in infield to drive in the game-winner.
"It's playoff baseball," Tigers manager Jim Leyland said. "Looked like we had one in hand and we let one get away, there's no question about that. But there have been two great games."
Boston's comeback came a few hours after Tom Brady threw a touchdown pass with 5 seconds left to complete the New England Patriots' comeback over the New Orleans Saints. The score was greeted with cheers by Red Sox fans waiting for the baseball game to start.
"We need it, man. We need start some momentum going on," Ortiz said. "The whole regular season, you haven't seen a team shutting us down for 14, 15 straight innings like they have the past couple of days. If you look at the way they've been pitching, (it's) unbelievable. It's up to us make an adjustment."
Miguel Cabrera and Alex Avila homered off Clay Buchholz as Detroit scored four in the sixth inning to open a 5-0 lead. The Red Sox got one in the bottom half but were four outs from falling behind 0-2 in the series when Ortiz tied it.
Scherzer, who led the majors with 21 wins, did not allow a hit until Victorino singled to left with two outs in the sixth.
It was an unprecedented third consecutive playoff game in which a Tigers starter took a no-hit bid into the sixth inning. That had never been done even twice in a row before this year's Detroit staff, which boasts the AL ERA leader, the major league leader in wins and the 2011 AL Cy Young winner and MVP.
"Scherzer was terrific. He was spent," Leyland said. "Last night our bullpen was flawless, and tonight it just wasn't quite as good."
In his first career ALCS start, Buchholz allowed five runs on eight hits in 5 2/3 innings while striking out six.
One night after Jon Lester absorbed a 1-0 loss, Buchholz kept the Red Sox in the game despite allowing three straight hits in the second and spotting Detroit to a 1-0 lead.
But Cabrera hit a solo shot off the light tower above the Green Monster in the sixth, then Fielder lined a double off the left-field wall. Victor Martinez followed with an RBI double to right-center and Avila hit a two-run shot over the Tigers bullpen to make it 5-0.
Scherzer continued to coast, striking out at least one batter in every inning. The favorite for the AL Cy Young Award after going 21-3 with a 2.90 ERA in the regular season, Scherzer allowed one run on two hits and two walks before leaving after seven innings with a 5-1 lead.
NOTES: Dave Roberts, whose stolen base sparked Boston's comeback in the 2004 ALCS against the New York Yankees, threw out the ceremonial first pitch. ... Ortiz's 63rd postseason game tied Jason Varitek for the Red Sox franchise record. ... Buchholz had a 1.20 ERA against the Tigers in four career starts at Fenway Park. ... Victorino's nine career hit by pitches in the postseason tie him with Alex Rodriguez for the major league record. .. Scherzer lost 2-1 at Fenway Park on Sept. 9 when going for his 20th win.