In the end, Miocic's patience paid off in a huge way, as he regained his UFC heavyweight title by TKO in Round 4 on Saturday in the main event of UFC 241 at Honda Center.
Miocic started landing body shots in the fourth, and though Cormier shrugged off the first two or three, they began to add up. It was a left hook to the body that started the sequence that led to Miocic's stoppage of Cormier at 4 minutes, 9 seconds.
With the finish, Miocic regained the crown he lost to Cormier by first-round knockout at UFC 226 in July 2018.
"I felt like that hook to the body was hurting him," Miocic said. "His hands were dropping, so I came over the top more. My coach told me to use that right hand. I knew I was hurting him. I just had to keep working, keep working until something opened up."
Before the fourth, it was Cormier's fight. Two judges had him ahead 29-28 going into the fourth round, and the other judge had Cormier winning all three rounds.
Cormier landed hard on the feet and took Miocic down in the first round. In the second, Cormier landed a series of nice jabs and right hands, and though Miocic started wearing damage, he was never hurt or rocked in the round.
Cormier fed Miocic a series of jabs in the third, but Miocic landed some power shots, including one that opened a cut either in or near Cormier's mouth.
With both men standing toe to toe, landing hard punches and showing off their incredible chins, Miocic mixed it up in the fourth round. He started landing left hooks and straight right hands to the body every chance he got. While Cormier was defending power rights to the head, Miocic was sneaking in hooks to the gut and side.
"I think he made a great adjustment," Cormier said.
Sonnen: Miocic's adjustment crucial to victory
Chael Sonnen breaks down how Stipe Miocic came out strong after being dominated in Round 1 and why Daniel Cormier didn't follow his corner's instructions. For more UFC, sign up here for ESPN+ http://plus.espn.com/ufc
Miocic landed a left hook to the body late in the round, followed by a one-two combination that rocked Cormier and sent him back against the cage. Miocic followed with a flurry, and referee Herb Dean stepped in for the clean stoppage.
"DC is a tough guy, I've got to give it to him," Miocic said. "I saw some weakness in that third round, and then in that fourth round, I caught him with that right hand, thank God, because he's tough."
Cormier landed a UFC heavyweight-record 181 significant strikes in the loss. Cormier and Miocic combined for 304 significant strikes, a new UFC heavyweight record.
Miocic (19-3), 36, held the record for consecutive UFC heavyweight title defenses before he fell to Cormier, and now he'll start a new reign. He has won seven of his past eight fights and has cemented himself as one of the best heavyweight MMA fighters of all time.
Miocic is now tied with Tim Sylvia for second in UFC history with five title fight victories. Randy Couture has the most, with six.
Cormier's (22-2, 1 NC) only previous loss came at light heavyweight to Jon Jones. The 40-year-old California resident has held titles at UFC heavyweight and light heavyweight. He is regarded as one of the best pound-for-pound MMA fighters ever.
Afterward, regarding retirement, Cormier said he'll have a discussion with his family and "make an educated decision as to what we're going to do."
UFC 241 drew a sellout crowd of 17,304 to Honda Center, setting a California gate record for MMA at $3,237,032.