Professional wrestler Robin Ramzinski, better known by his ring name Randy "The Ram" Robinson, rose to fame in the 1980s. Now past his prime, Randy wrestles on weekends for independent promotions in New Jersey while living in a trailer park and working part-time at a supermarket under Wayne, a demeaning manager who mocks Randy's wrestling background. As a regular at a strip club, Randy befriends a stripper named Cassidy who, like Randy, is past her prime. After winning a local match, Randy agrees to a proposed 20th-anniversary rematch with his most notable opponent, "The Ayatollah", which Randy hopes could return him to stardom.
Randy intensifies his training, which includes steroid injections. After wrestling in a hardcore match, Randy suffers a heart attack backstage and undergoes coronary artery bypass surgery. His doctor informs him that he nearly died and has to stop taking steroids, and also warns Randy not to wrestle anymore, as his heart can no longer handle the exertion. Reluctantly, Randy decides to retire and begins working a full-time shift at the supermarket's deli counter.
At Cassidy's suggestion, Randy visits his estranged daughter Stephanie, whom he had abandoned when she was a child, but she rebuffs him. While helping Randy buy a gift for Stephanie, Cassidy reveals that she has a son. Randy makes romantic advances toward her, which she rejects on the grounds of her job. Later, Randy gives the gift to his daughter and apologizes for abandoning her. The two bond over a visit to a beachfront boardwalk, where he often took her as a child, and agree to meet for dinner on the coming Saturday.
Randy goes to Cassidy's strip club to thank her, but she once more rejects him, resulting in a heated exchange. Upset, Randy goes to see a wrestling match and finds solace in his wrestling friends. While at a bar with them, he gets drunk, snorts cocaine, has sex with a woman in the women's restroom, then wakes up in her bedroom the next morning. Exhausted, he sleeps the entire day and misses his dinner with Stephanie. He goes to her house to apologize, but she angrily tells him she hates him and never wants to see him again.
At the deli counter, a patron recognizes Randy as the wrestler, though he denies it. The customer persists, which agitates Randy, who then cuts his own hand on the slicer and promptly quits on the spot, going into a rampage in the store while insulting Wayne and the customers. Spurred by the fan's recognition of him and with nothing left, Randy decides to return to wrestling and reschedules the rematch with The Ayatollah. He reconciles with Cassidy, who has also just quit her job, though she begs him not to wrestle because of his heart condition and pleads with him to cancel the match. However, Randy disregards her advice, explaining to her that he belongs in the ring with his fans and fellow wrestlers who love and respect him.
As he wrestles, Randy begins to feel chest pain and becomes unsteady. Noticing this, The Ayatollah urges him to initiate the pin and end the match. Randy refuses, however, and climbs the top rope for his signature finishing move, a diving headbutt called the "Ram Jam". He looks over and sees Cassidy has left. As the crowd cheers his name, Randy, with tears in his eyes and smiling from his fans' cheers, leaps from the top rope.