Benny (Mike Vitar) has a dream where Babe Ruth (Art LaFleur) comes to visit him. Babe knows of how the baseball with his signature on it owned by the stepfather of Smalls (Tom Guiry), Bill (Denis Leary), ended up in the yard of "The Beast," a huge bullmastiff, and though he tells Benny to just go and get it, he warns Babe of the Beast. Babe sits him down and tells him that everybody gets one chance to do something great, but most people never take that chance either because they are too scared or they don't recognize it when it spits on their shoes. Benny manages to deduce from that that his moment of greatness will come when he pickles the Beast.
The next day, Benny, Smalls, and the rest of the gang head to the Sandlot, where Benny adorns PF Flyer sneakers, said to make someone run faster and jump higher. Benny enters the yard, encounters the Beast, but he snags the now-wrecked ball and escapes. However, the victory was short-lived, for the Beast hopped over the fence soon after and began chasing Benny around town. The chase leads back to the Sandlot, where Benny re-hops the fence and crashes on his back. The Beast breaks his way through the fence, but then the fence falls over on top of him and pins him underneath. As the Beast whimpers in pain, Smalls decides to go to his aid, and with Benny's help they lift the fence off the Beast. The Beast then comes up to Smalls and licks his face in gratitude. Then, the Beast goes behind a pile of junk and starts digging, and Benny, Smalls, and the rest of the Sandlot crew go check it out. They find all the balls they knocked into the yard, a way of the Beast giving them their balls back.
Benny & Smalls knock on the back door of the house, where Mr. Mertle (James Earl Jones), the man who owned the dog and is blind, answers. Smalls tells him they brought his dog home, and Mertle addresses the dog by his real name of Hercules. He asks how he got out, and Benny tells him it was to retrieve a ball, and Mertle asks for the ball. After some more talking they are invited inside, and taken into a room loaded with baseball paraphernalia. Smalls tells Mertle the ball was his stepdad's and was signed by Babe Ruth, and Mr. Mertle says that Smalls was dead where he stood for taking the ball and wrecking it. He then goes to a cabinet and takes out an old baseball saying he'd trade Smalls for it. He points out that this ball was autographed by the 1927 New York Yankees, Babe Ruth's signature amongst the others. It is revealed that Mr. Mertle was a baseball player and personally knew Babe Ruth, and he said he would've broken Babe's record had he not been hit by a high fast ball to his head and been blinded. He decides to give them the Yankees ball if they'd come over once a week to talk baseball with him. They agree to his offer.
Smalls, in the narrative (voiced by David M. Evans), said Bill was pretty mad about him taking his Babe Ruth ball and ruining it, grounding him for a week, but he loved the 1927 Yankees ball. Smalls from then on had no problem calling him "dad" and could finally play catch with him. Smalls said that the gang continued to play ball during the summers that followed up until junior high, and whenever one moved away, they never replaced him on the team. They kept playing like he was still there.
He kept in touch with the Sandlot crew over the years, and he says the fate of each:
It then cuts to the present, where it shows that Smalls is the baseball radio commentator seen earlier in the film (and owns the Yankees ball, wrecked Babe Ruth ball, and fake Babe Ruth ball), and he commentates while Benny, in the twilight of his career playing for the Los Angeles Dodgers in Major League Baseball, steals home. They give each other the thumbs up, and after that a smiling Smalls looks at the wall, and the camera pans to a picture of the whole Sandlot crew before the end credits roll.
Thanks Tornado Dragon!