All Manny Pacquiao could do was laugh after he once again was on the wrong end of a highly controversial decision.

He engaged in a surprisingly close fight with massive underdog Jeff Horn but seemed to pull away over the final four rounds. The judges in Horn’s hometown of Brisbane, Australia — before 51,052 at Suncorp Stadium — saw it quite differently.

They turned in tallies of 115-113, 117-111 and 115-113 for Horn, a 29-year-old former school teacher who won the WBO welterweight title Saturday night in the debut of Top Rank’s new series on ESPN.

“I guess it’s the crowd behind me and all the support,” an elated Horn said, his right eye bloody and badly bruised.

Referee Mark Nelson almost stopped the fight following Round 9, when Horn was absolutely battered but somehow didn’t go down.

“Show me something in this next round or I’m gonna stop the fight,” Nelson instructed.

Horn did just that, showing great fitness and determination. He plowed forward in that round as he did all night and reached the final bell. But did he win? It didn’t appear so.

“I wasn’t really that hurt,” Horn (17-0-1, 11 knockouts) insisted, referring to the round in which he was rocked around the ring. “I was a little bit buzzed, but I recovered very quickly. I thought i was winning the fight at that stage. I thought I was coming forward more and landing the cleaner blows.”

There’s a rematch clause in the contract, and both fighters expressed great interest in a return meeting of the highly entertaining slugfest.

“Absolutely, yes. Rematch, no problem. No doubt about it.” said Pacquiao (59-7-2-38 KOs), who lost to Tim Bradley — who was at ringside to call the action — via a hotly debated decision in 2012. ” … I didn’t expect his toughness. I tried knocking him out in Round 9, but he survived.

“I’m a professional; I respect the judges. He’s tough, and he survived that round.”

Pacquiao, who looked all of his 38 years on this night, did say afterward, “I don’t like to complain, but when I arrive here (in Australia), I catch cold.”

Horn was given no chance to compete, let alone win, by oddsmakers and media alike, but he stunned Pacquiao with his aggressive approach right out of the gate.

“The Hornet” pinned Pacquiao on the ropes in Round 1 and connected with some effective body blows, along with a few uppercuts to the head. Horn was dropped in two of his last three bouts entering the Pacquiao bout, but his chin held up against boxing’s only eight-division champion ever, round after round.

While he was aggressive, he was far from accurate. Horn landed just 15 percent of his punches (92 of 625), per CompuBox; the Filipino senator connected on 182 of 573 (31.8 percent).

Horn’s awkward movement, size and non-stop pressure troubled Pacquiao early, and eventually the Aussie was able to hurt the champ in Round 6 with a straight right, no doubt to the shock of the millions watching Pacquiao’s first non-pay-per-view bout since 2005.

Horn pressured recklessly and led with his head at times. A clash of heads opened up a nasty cut over the right side of Pacquiao’s hairline in the sixth. Moments earlier, Pacquiao was pinned on the ropes when Horn banged the body followed by clean right uppercut.

The following round, another clash of heads opened up a gash on the opposite of the southpaw’s hairline, and he too, was now a bloody mess.

Pacquiao, though, finally timed Horn. He buzzed Horn with a left hook in Round 8, and then proceeded to absolutely pummel the underdog in Round 9. Horn was swaying around the ring on wobbly legs but somehow stood up to 29 connects, by far Pacquiao’s best round of the night.

Nelson almost stopped the contest, but Horn protested and pressed on, toe-to-toe with an all-time great.

When Michael Buffer set out to announce the final decision, it seemed a formality: Pacquiao would retain his title via unanimous decision. But it wasn’t to be. Pacquiao showed his age, after so many brutal wars, but he still seemed to win the fight.

Now, it looks as if Pacquiao and Horn will do it one more time. Who could have imagined that just 24 hours earlier?

Mike Coppinger is the Senior Writer for RingTV.com. Follow him on Twitter: @MikeCoppinger