Creed

In 1998, Adonis "Donnie" Johnson—the son of former heavyweight champion Apollo Creed via an extramarital affair—is serving time in a Los Angeles youth detention center when Apollo's widow, Mary Anne Creed, visits and offers to take him in.
In the present time, Adonis is in Tijuana, Mexico, preparing for his match in an amateur boxing bout hosted in a bar. Upon returning from his latest fight, Adonis resigns from the Smith Boardley Financial Group to pursue his dream of becoming a professional boxer. Adonis auditions at Los Angeles' elite Delphi Boxing Academy, managed by family friend Tony "Little Duke" Evers Jr., the son of Apollo's trainer Tony "Duke" Evers, but is turned down. This rejection is further emphasized as Adonis is beaten in a sparring match by heavyweight champion and #2-pound-for-pound Danny "Wheelman" Wheeler after he publicly challenges the whole gym to prove himself, betting his 1967 Ford Mustang that no one can get a clean head shot on him. Mary Anne vehemently opposes his aspirations, remembering how her husband was killed in the ring by Ivan Drago thirty years ago. Undaunted, Adonis moves to Philadelphia in hopes of getting in touch with his father's old rival-turned-friend, former heavyweight champion, Rocky Balboa.
Adonis meets Rocky at a restaurant known as Adrian's, named in honor of his deceased wife, and asks Rocky to become his trainer. Rocky is reluctant to return to boxing due to having bad prior experiences as a trainer, but eventually agrees. Adonis asks him about the "secret third fight" between him and Apollo just after Apollo helped Rocky regain the heavyweight title, and Rocky reveals that Apollo won. Adonis trains at the Front Street Gym, with several of Rocky's longtime friends as cornermen. He also finds a love interest in Bianca, an aspiring singer and songwriter in the early stages of progressive hearing loss.
Adonis, using his biological mother's surname, Johnson, and the fight name "Hollywood", defeats local fighter Leo "The Lion" Sporino, which upsets the opposing corner. This leads to the opposing side leaking the news that Adonis is Apollo's illegitimate son. Rocky receives a call from the handlers of World Light Heavyweight Champion "Pretty" Ricky Conlan, who is being forced into retirement by an impending prison term. He offers to make Adonis his final challenger—provided that he fights using his father's surname, Creed. Adonis is hesitant at first, wanting to forge his own legacy. However, he eventually agrees with a little convincing from Bianca.
While helping Adonis train, Rocky suddenly collapses and is admitted to the hospital. Through further testing, he is diagnosed with non-Hodgkin's lymphoma. He is unwilling to undergo chemotherapy, citing its inability to save Adrian when she had ovarian cancer. The fact that his best friend and brother-in-law Paulie Pennino has now died along with all of his other friends as well as his estrangement from his son consign him to accept his eventual death. Adonis later finds out and urges him to seek treatment, but leaves in frustration after Rocky refuses and tells him he never truly believed they were a family. This causes him to lash out and get in a fight with an attendee at Bianca's concert after he compares him to his father, and is sent in jail. After being bailed out, Adonis refuses to train for his fight with Conlan if Rocky doesn't accept treatment, which Rocky finally agrees to.
Adonis fights Conlan at Goodison Park in Conlan's hometown of Liverpool, and many parallels emerge between the ensuing bout and Apollo and Rocky's first fight forty years earlier. First, before entering the ring, Adonis receives a present from Mary Anne – new American flag trunks similar to the ones Apollo and later Rocky wore. Additionally, to the surprise of nearly everyone, Adonis gives Conlan all he can handle. Conlan knocks Adonis down, but Adonis recovers to knock Conlan down for the first time in his career. Adonis goes the distance, but Conlan wins on a split decision. However, Adonis has won the respect of Conlan and the crowd through his efforts. As Max Kellerman puts it while calling the fight for HBO, "Ricky Conlan wins the fight, Adonis Creed wins the night." Conlan tells Adonis that he is the future of the light heavyweight division.
The film ends with Adonis and a frail but improving Rocky climbing the steps outside the entrance of the Philadelphia Museum of Art.