He took so much in the ninth round that the referee almost stopped the fight in his corner. Horn went on to make the Australian Olympic team and is now a school teacher and top contender in boxing.
Pacquiao appeared to control most of the fight, with Horn sticking with him for most of the way.
However, Horn was allowed to continue, and gave a strong effort in Rounds 10, 11 and 12, though he took a severe punishment in the process.
Tubelight flickers post Rs 100-crore mark on Box Office collection
With director Kabir Khan , this is the second film by the duo after the massive success of " Bajrangi Bhaijaan ". Salman Khan and Kabir Khan produced the film, under the banner, Salman Khan Films and Kabir Khan Films.
But the judges scored it differently, awarding the fight to Horn by unanimous decision with scores of 117-111, 115-113 and 115-113. Analyst Teddy Atlas called it a "hometown decision".
Pacquiao (59-7-2, 38 KOs) has been here before, losing a decision and a welterweight title to Timothy Bradley Jr.by split decision in 2012 in one of the most controversial decisions in boxing history. If Horn beats Pacquiao he would be an instant star in Australia, and his chapter into boxing super stardom just begins.
Pacquiao's fans took to Twitter to slam the judges' decision, labelling it as "robbery". After his shock defeat earlier today, the Filipino legend has reportedly said he is ready for a rematch later this year against Horn.