Australia’s Jeff Horn stunned Filipino Manny Pacquiao in a bloody Brisbane battle to claim a unanimous 12-round decision and win the WBO world welterweight title in front of 50,000 fans at Lang Park on Sunday.

The unheralded 29-year-old former schoolteacher, who improved his record to 17-0-1, was awarded the win over the eight-division world champion by scores of 117-111, 115-113 and 115-113.

“I take massive confidence from this fight,” said Horn afterwards, saying he had climbed the “Pacquiao mountain”.

Pacquiao, one of the finest boxers of his generation, paid the price for a slow start and his inability to end the fight with a knockout.

The 38-year-old was knocked off his stride by the aggression of the taller and heavier Australian in the early rounds but looked to have weathered the storm as the fight wore on and Horn tired.

The Australian showed remarkable powers of recuperation as he battled gamely on through the final three rounds with Pacquiao, who earned the last of his 38 knockouts in 2009, unable to capitalise on his dominance.

The bout ended with the fighters in a clinch on the ropes and although Pacquiao gave a little shuffle and a grin to show he had plenty left in the tank, his fate was in the hands of the judges who marked him narrowly down.