Freddie Freeman described his walk-off grand slam as a dream come true on Friday after helping the Los Angeles Dodgers snatch a jaw-dropping World Series game one victory over the New York Yankees.

Freeman's 10th-inning blast - the first ever walk-off grand slam in a World Series game - was the latest improbable twist to what has been a roller-coaster season for the 35-year-old first baseman.

Freeman, an avid student of the game, was delighted to learn he had etched his name into baseball history with his winning homer.

"That's pretty cool," Freeman said. "Obviously it's kind of amazing. When you get told you do something like that in this game that's been around a very long time -- I love the history of this game, to be a part of it, it's special.

"I've been playing this game a long time, and to come up in those moments, you dream about those moments even when you're 35 and been in the league for 15 years, you want to be a part of those."

The fact that Freeman has made it to the postseason is a minor miracle in itself after a challenging year beset by injuries, all overshadowed by a serious illness for his three-year-old son, Max.

An emotional Freeman returned to play later that month but then saw his postseason hopes clouded by a serious ankle sprain in late September that left him barely able to run.

After celebrating his walk-off with team-mates, Freeman sprinted over to the seats behind home plate to share a moment with his father.

"He's been throwing me batting practice since I can remember," Freeman said. "My swing is because of him. My approach is because of him. I am who I am because of him. It was kind of spur of the moment."

Dodgers manager Dave Roberts meanwhile believed that Freeman's moment of glory was just reward for one of the most popular players in baseball.

"The game honors you, and when you do things the right way, you play the right way, you're a good team-mate, I just believe that the game honors you," Roberts said. "Tonight Freddie was honored. (AFP)