One day, Benny hits the cover off the team's only ball, much to the team's amazement. With Bill away on business for a week, Smalls opts to keep the game going, by borrowing his prized baseball autographed by Babe Ruth. Unaware of its value, Smalls hits his first home run, sending it into the Beast's yard. When the team learns of the autograph, they quickly buy another baseball, and forge Babe Ruth's signature on it to be a temporary replacement while they come up with a plan to rescue the autographed ball. Smalls suggests going to Mr. Mertle for assistance, but Squints insists Mr. Mertle will not help them. The team attempts to recover the lost ball with various makeshift devices, but each attempt is thwarted by the Beast. As Smalls prepares to accept his fate, Benny dreams of the spirit of Babe Ruth, who advises him to rescue the ball himself. "Heroes get remembered, but legends never die," says the Babe. "Follow your heart, kid, and you'll never go wrong."
Equipped with a new pair of PF Flyers, Benny retrieves the ball by "pickling" the Beast and leaping back over the fence, but the dog breaks its chain and chases him through town. Benny races back to Mr. Mertle's yard, but the Beast crashes through the fence, and it falls down on top of him. Smalls and Benny free the Beast, who gratefully licks Smalls' face and leads them to its stash of baseballs. The two meet Mr. Mertle, who turns out to have been a baseball player and friendly rival of Babe Ruth, having lost his sight after being struck by a pitch. He kindly trades them the chewed-up ball for one autographed by all the Murderer’s Row and asks them to visit every week to talk baseball.
Bill loves the Murderer's Row ball, but still grounds Smalls for a week for taking and ruining his Babe Ruth autographed ball. Their relationship improves and Smalls begins to call him "Dad". The boys continue to play on the sandlot the rest of that summer, and several subsequent summers with the Beast – whose real name is Hercules – as their mascot. As the years pass, the boys eventually go their separate ways: Yeah-Yeah enlists in the army and later becomes one of the pioneering developers of bungee jumping; Bertram disappears into the counterculture movement; Timmy and Tommy become an architect and a contractor and become wealthy upon inventing mini-malls; Squints marries Wendy, has nine kids with her, and the two run the local drug store; Ham becomes a professional wrestler: "The Great Hambino"; DeNunez plays triple-A baseball, but later owns a business and coaches his sons' Little League team: The Heaters; and Benny earns the nickname "the Jet" after word spreads around about his encounter with the Beast.
As an adult, Smalls becomes a sports commentator and remains friends with Benny, now a player for the Los Angeles Dodgers. Performing the play-by-play for a Dodgers game, Smalls cheers Benny on as he steals home to win the game against the San Francisco Giants, and they give each other the same thumbs-up sign they have shared since childhood. In Smalls' broadcast booth, he owns and keeps on display the chewed-up Babe Ruth autographed ball, the Murderer's Row ball, the forged Babe Ruth ball, some pictures of Babe Ruth, and a large picture of the Sandlot kids from 1962.