Rounds 1–4

The first four rounds of the first Marciano–Charles bout revealed Charles's superior technical expertise. Marciano was outfought and outmaneuvered in these early rounds. Charles threw body shots at Marciano with great success; he also opened a two inch long and one inch deep cut over Marciano's left eye.^[9][10] Marciano's cut man Freddie Brown, who later worked for Roberto Durán, would comment that he could not remember treating a cut worse than this one.^[11]

Rounds 5–9

In the fifth round, Charles surprisingly became defensive and stopped dictating the pace of the fight. In the early rounds, Charles had thrown body punches at Marciano with great success; by the fifth round Charles was no longer throwing these punches. Without making any effort to protect his eye, Marciano carried the fight to Charles, went on the offensive, found his rhythm, and seized the initiative in the fight. By the end of round 9, Marciano's face was a crimson mask, and yet he had managed to land so many punches on Charles that he was ahead in the scoring.^[11][12][3]

Rounds 10–15

By the 10th round, Marciano was clearly ahead and yet he kept fighting as if the decision was in doubt, and kept trying for a knockout. Charles managed to stay on his feet while withstanding Marciano's punches, but his face gradually started changing for the worse. His right eye closed, his lower lip was split and swollen, and a blood clot appeared on his left jaw. At the end Marciano won the fight with a unanimous decision (scored 8-5, 9-5 and 8-6 in favor of the champion).^[11][13] Ruby Goldstein, who refereed this fight, commented:

Charles was a very good, smart fighter, who still employed the tactics he had as a middleweight.He gave Marciano trouble for the first ten rounds.He came at him fast with an assortment of punches, and he hit Rocky with a lot of combinations where he'd put together five or six punches in a row.Most fighters would grab on and wait for their head to clear after being hit by a good combination. But this is where Marciano was a discouraging-type fighter. After a fighter hit him with some of his best punches, Rocky would come chasing right back after him, back him up against the ropes, and throw seven or eight punches of his own.^[14]

Early rounds

Charles won the first round by landing some clean punches on Marciano's jaw. In the second round, Marciano hit Charles with a body blow, and then knocked Charles down on the canvas. Marciano now went for the kill, but Charles proved too slippery and survived the round. The fight then became an offensive–defensive affair with Marciano constantly on the attack and Charles content to do defensive boxing while throwing only occasional punches. The fight became dull and insipid with about the only excitement coming from Marciano's usage of roughhouse tactics like throwing low blows and hitting after the bell. The fouls did not affect the judges who had Marciano well ahead after the fifth round.^[15][16]

A twist in the tale

Something strange happened in the sixth round because of which Ezzard Charles almost won the fight. As Charles and Marciano emerged from a clinch towards the end of the round, Marciano was seen sporting a deep wound on his left nostril. It was unclear how Marciano got hurt with some claiming it was due to Charles's punches, and Marciano laying the blame on Charles's elbow. Marciano now started bleeding profusely from the wound; he would later observe: "I knew something was wrong because the blood was running like from a faucet. "Meanwhile, Charles's corner was feeling triumphant after the sixth round; Charles was advised by them to keep throwing punches at Marciano's nose.^[15][17]

Seventh round

In the seventh round, Marciano went out with a makeshift patch over his nose; the device was quickly knocked off by Charles's punches as Charles went after Marciano's nose. Remarkably enough, Marciano won the seventh round by landing more blows than Charles who was left staggered at the end of the round. Even so, it was Marciano who was in danger because of the nose wound which continued to gush blood. The word was out that the fight would only be allowed to continue for one or two more rounds.^[15][18]

Eighth round

In the interval before the eighth round, Marciano's corner advised him to go after Charles's body. Instead, he decided to ignore the advice and went after his opponent's head. As Marciano later explained:

I was spilling too much blood, and they might have stopped it. I like my title too much to lose it on account of a little blood. I don't knock 'em out in the body. I knock 'em out on the chin.^[18]

With 24 seconds left for the end of the eighth round, Ezzard Charles was knocked out by Marciano.^[15] It was later suggested that the extra weight Charles had put on for this fight resulted in him providing a slower target for Marciano.^[19]