Pacquiao entered the bout with a 59-6-2 record, the WBO welterweight championship, and a reputation as one of the greatest fighters in boxing history. At 38 years elderly, he was still competing at a high level and was a ponderous betting favorite against Horn, an undefeated but largely untested mandatory challenger from Australia who brought a 16-0-1 record into the biggest fight of his career.

From the opening bell, Horn fought with relentless aggression. Rather than trying to outbox Pacquiao, he crowded him, leaned on him, attacked the body and forced the champion to fight at an uncomfortable pace. Horn’s physical style included constant clinches and several accidental head clashes that left Pacquiao bleeding from cuts on his hairline and near his left eye.

After Horn claimed the opening round with his pressure, Pacquiao settled into the fight. His trademark straight left hands, quick combinations and superior accuracy began finding the target as he took control through the middle rounds. By the third round, he had opened a cut over Horn’s right eye, and his cleaner punching repeatedly beat the Australian’s volume attack.

The fight reached its turning point in the ninth round.

Pacquiao unleashed a sustained barrage of left hands and combinations that badly hurt Horn, who staggered around the ring absorbing ponderous punishment. Referee Mark Nelson even warned Horn’s corner before the final round that their fighter needed to show something or the contest could be stopped. Many viewers believed Horn was only moments away from suffering the first defeat of his professional career.

Instead, Horn survived the assault, regrouped over the final three rounds and continued pressing forward until the final bell.

When the scorecards were announced, judge Waleska Roldan scored the fight 117-111 for Horn, while Chris Flores and Ramon Cerdan each had it 115-113 for the hometown challenger.

The verdict immediately sparked outrage throughout the boxing world.

Many respected media members scored the fight comfortably for Pacquiao. ESPN’s Dan Rafael had it 117-111 for the champion, while analyst Teddy Atlas scored it 116-111. Of 15 major media scorecards compiled after the fight, 12 favored Pacquiao, two favored Horn and one scored it even. CompuBox statistics also strongly favored Pacquiao, who landed 182 of 573 punches (32 percent) compared to Horn’s 92 of 625 (15 percent), nearly doubling Horn’s total connects while outlanding him in 11 of the 12 rounds.

The controversy became so significant that Philippine officials requested the WBO review the scoring. After conducting its review, the sanctioning body upheld the official result, with its independent panel narrowly favoring Horn despite acknowledging how close and subjective several rounds had been.

Although Pacquiao exercised his contractual right to pursue a rematch, it never materialized. Discussions for a second fight later that year collapsed because of Pacquiao’s duties as a Philippine senator, and the matchup was never revisited.

For Horn, the victory became the defining moment of his career. He made one successful defense of the WBO title before losing it to Terence Crawford in 2018. Pacquiao, meanwhile, silenced suggestions that he was finished by capturing another world title two years later, defeating Keith Thurman to win the WBA welterweight championship at age 40.

Nearly a decade later, Horn’s upset remains one of the most controversial championship decisions of the contemporary era. Pacquiao landed far more punches, while Horn’s pressure and aggression persuaded the judges, making the “Battle of Brisbane” one of the most debated fights of the 2010s.