Freeman slam lifts Dodgers over Yankees in thrilling World Series opener
Freeman, restored to the line-up after a nagging ankle injury, cracked a 423-foot two-out home run in the 10th inning to hand the Dodgers an electrifying victory at Dodger Stadium.
The Yankees looked to have snatched a precious advantage after Jazz Chisholm scampered home to give the Bronx Bombers a 3-2 lead in the top of the 10th.
The Dodgers were then left staring at defeat after watching the Yankees notch two outs in the bottom of the inning to stand on the brink of victory.
But after New York loaded the bases with an intentional walk of Mookie Betts, Freeman stepped up to the plate with one last chance to snatch victory.
Yankees reliever Nestor Cortes sent down a 92mph fastball and Freeman caught it on the full and sent it soaring into right field in a moment of pure theatre that was straight out of Hollywood.
"That's a dream come true," Freeman said after his winning moon shot - the first walk-off grand slam in a World Series game. "But it's only one, we've got three more."
Game 2 in the best-of-seven series takes place on Saturday.
Former MVP Freeman has struggled to find his best form this postseason after turning an ankle just before the playoffs.
But the 35-year-old first baseman delivered in the clutch with a moment that is destined to become part of the folklore of World Series history.
An elated Freeman joked that he had almost had an out-of-body experience as he rounded the bases before being mobbed by teammates as roars of "Freddie, Freddie" cascaded down from the sold-out Dodger Stadium stands.
'Floating' Freeman
"It felt like nothing, just kind of floating," Freeman said. "Those are the kind of things, when you're five years old with your two older brothers and you're playing wiffle ball in the backyard, those are the scenarios you dream about, two outs, bases loaded in a World Series game.
"For it to actually happen and get a home run and walk it off to give us a 1-0 lead, that's as good as it gets right there."
The defeat was desperately cruel on the Yankees, who behind a superb pitching performance from starter Gerrit Cole had largely kept the Dodgers' vaunted offence led by Shohei Ohtani quiet.
The Dodgers had taken the lead with a run from Enrique Hernandez in the fifth inning after Will Smith's sacrifice fly.
But the Yankees hit back in the sixth inning with a two-run home run from Giancarlo Stanton to take a 2-1 lead.
The Dodgers tied it up in the bottom of the eighth inning after Betts' sacrifice fly allowed Ohtani to come home.
That sent the game to extra-innings and the Yankees appeared poised to snatch victory after Chisholm scored.
But Freeman provided a startling full-stop to a night of nerve-shredding drama as the hoped-for blockbuster between the two historical rivals unfolded.
The Yankees and Dodgers, arguably the two most iconic franchises in Major League Baseball, are meeting in the World Series for a 12th time and for the first time since 1981.
Hype surrounding this year's Fall Classic has cranked into overdrive due to the big-hitting exploits of Dodgers superstar Ohtani and Yankees captain Aaron Judge.
But in the event, Ohtani and Judge were forced out of the spotlight by Freeman's inspired winner.
"It might be the greatest baseball moment I've ever witnessed, and I've witnessed some great ones," Dodgers manager Dave Roberts said of Freeman's winner.
"Once they decided to walk Mookie, I just felt good with Freddie at the plate. And just that swing, you knew it was gone.
"Just pure elation. You don't see teams celebrate after a game, a walk-off like that, but I just think it was certainly warranted. It was a great game before that, but the way it finished - I just couldn't be more excited for our guys."
Yankees manager Aaron Boone meanwhile defended the decision to walk Betts to allow Freeman to come to the plate.
"Just taking the left-on-left match-up there," Boone said of the decision to walk Betts. "I didn't deliberate long."
