Battered and bruised after scaling 'Pacquiao Mountain', new WBO welterweight champion Jeff Horn says he is dead serious about fighting Floyd Mayweather Jr.

And Horn's trainer, Glenn Rushton, reckons he knows how to beat him.

The 29-year-old has set himself yet another lofty goal after Sunday's points win over Pacquiao, one of the greatest boxers of the era.

Asked who he would take on next if it was all up to him, Horn said:

"Good question. Obviously a Mayweather fight would be a great fight. I'd probably prefer that one rather than any other one."

The first thing Horn did after his 'Battle of Brisbane' victory was to call out Mayweather, who has won all 49 of his professional fights and is coming out of retirement to face UFC star Conor McGregor on August 26.

"We're serious. We want the fight," Horn said. "He's an old guy as well, he's over 40.

"They all laughed when I was meant to fight Pacquiao and said it wouldn't last three rounds. Why not get in there with someone like Mayweather?"

Many saw the Pacquiao win as controversial, but Top Rank promoter Bob Arum said the result of the Pacquiao was a close call after some close rounds late in the bout as both fighters looked for a decisive blow.

"It was a close fight, it could have gone either way," said Arum. "A couple of close rounds, but you can't argue with the result."

"I scored a lot of the early rounds for Jeff. Then I had Manny coming back in the middle. The 12th round, Jeff really won. If you give Manny the 11th, you have it a draw. You give Jeff the 11th, it's 7-5."

Pacquiao's long-time trainer Freddie Roach predicted the fight would be short and sweet but Horn - unbeaten in his 17 previous professional fights - applied pressure by winning some of the early rounds and Pacquiao needed treatment during the 6th and 7th rounds for a cut on the top of his head that resulted from a clash of heads. The judges scored the fight 117-111, 115-113 and 115-113.