Freddie Freeman has hit the first game-ending grand slam in World Series history with two outs in the 10th inning to give the Los Angeles Dodgers a 6-3 victory over the New York Yankees in a dramatic opener.

Hobbled by a badly sprained ankle, Freeman homered on the first pitch he saw, an inside fastball from Nestor Cortes, and raised his bat high before beginning his trot as the sellout crowd of 52,394 roared on.

“I cannot believe what just happened,” Dodgers manager Dave Roberts said.

“That’s what makes the Fall Classic a classic, right, because the stars come out and superstars make big plays, get big hits, in the biggest of moments ... I’m speechless right now.”

Freeman, who missed three games during the National League playoffs because of the injury to his right ankle, didn’t have an extra-base hit this post-season until legging out a triple earlier on Friday.

“The last six days we treated it really well. I’ve been feeling pretty good,” Freeman said.

“Right when I ran out to give high-fives to my teammates, I felt pretty good, because that was the first time I ran all week. So, ankle’s good.”

In this much-hyped, star-studded World Series between two of baseball’s most storied and successful franchises, Game 1 certainly delivered. It was the third straight Series opener to go extra innings.

“We can’t sit here and mope,” Yankees slugger Aaron Judge said.

“Learn from it, where we can improve, and try to win the next one.”

In the top of the 10th, Anthony Volpe grounded into a fielder’s choice to shortstop, scoring Jazz Chisholm Jr. from third after he stole two bases, to give the Yankees a 3-2 lead.

But the Dodgers weren’t done.

Gavin Lux walked against Jake Cousins with one out in the bottom of the 10th and went to second on Tommy Edman’s infield single to second.

That brought up star slugger Shohei Ohtani, a left-handed hitter. Yankees manager Aaron Boone went to his bullpen again for Cortes, a lefty starter who hadn’t pitched since September 18 because of an elbow injury.

After missing the American League playoffs, Cortes was added to the World Series roster on game day.

Left fielder Alex Verdugo made a running catch in foul territory to retire Ohtani. Verdugo’s momentum sent him tumbling over the low retaining wall, advancing both runners one base because by rule it became a dead ball when Verdugo wound up in the stands.

With first base open, New York intentionally walked Mookie Betts to load the bases and set up lefty-on-lefty matchup of Cortes against Freeman.

“I was on time for the heater,” Freeman said.

His drive into the right-field pavilion sent Dodgers fans into a frenzy. It was the third walk-off homer in World Series history for a team that was trailing.

“That’s stuff, you’re five years old in the backyard right there,” Freeman added.

“That’s a dream come true, but it’s only one. We’ve got three more.”

It’s the 12th time the Yankees and Dodgers are meeting in the World Series, the most frequent matchup in major league annals, but their previous October clash was 43 years ago.

While the Dodgers are seeking their eighth title and second in five years, the Yankees are in the Fall Classic for the first time since winning No. 27 in 2009.