"I'm so desperately sorry for you all," Hatton told his followers. "I thought I would win but it went wrong.
"I'm OK but so upset for all the supporters who came out here."
About 20,000 fans are thought to have made the trip from Britain to see Hatton fight.But they witnessed less than six minutes of action as Hatton suffered only the second loss of his 47-fight career.
The Mancunian was knocked down twice in the first round before being counted out with one second left of round two after being floored by a huge left from his Filipino opponent.
"I didn't see the punch coming, but it was a great shot," said Hatton. "I congratulate Manny. He is a terrific fighter."
Despite the manner of his defeat, Hatton was able to host a poolside party at the MGM Grand Hotel on Sunday, appearing relaxed and unmarked.
He posed for pictures with his younger brother Matthew, who won his welterweight fight on the undercard.
Meanwhile, the Hatton camp moved to play down talk of a rift between American trainer Floyd Mayweather Sr and English assistant trainer Lee Beard, which was raised as a possible contributory factor to the defeat.
"It's an interesting point, but the one person to blame is Pacquiao," said Hatton Promotions chief executive Gareth Williams.
Mayweather Sr appeared at the post-fight press conference but only briefly, and he did not sit on the chairs and take questions alongside Beard and Williams.
"Lee's a lot more involved with Ricky Hatton than Floyd Mayweather is," Williams added. "Floyd Mayweather was brought in for 12 weeks to do a job, and that's the end of it.
"He's finished now and we don't know what's going to happen. Lee Beard's with Hatton Promotions 365 days a year, Floyd Mayweather's there for 12 weeks before a fight, and that's the difference.
"Probably the best way to describe Floyd is that he's on board as a consultant. He doesn't control Ricky Hatton, he doesn't speak for Ricky Hatton, he speaks for Floyd Mayweather."