LAS VEGAS — Manny Pacquiao acts as though it’s personal, then claims it’s not. Just another night in the ring, another notch on his belt and another $25 million or so to take back to the Philippines with him.

It’s not that easy for Juan Manuel Marquez. He remains convinced he won both of his previous two fights with Pacquiao, and he will enter the ring tonight as eager for redemption as he is to claim the biggest payday of his long boxing career.

“I hope the judges score what they see, not like the other two fights when they were not impartial,” Marquez says.

The judges may not be necessary this time around. Marquez has bulked up for the 144-pound fight so he can bring more power into the ring, and Pacquiao — who knocked Marquez down four times in their two fights — is a far more potent puncher than the last time they met three years ago.

Add in the fact these two fighters throw punches almost nonstop, and there’s potential for an early ending.

“I’m not thinking about the knockout,” Pacquiao said. “If the knockout comes, that’s just the bonus for your sacrifices in training.”

Pacquiao returns to the ring for the first time since he beat Shane Mosley in May, fighting a familiar foe in a bout that will earn him yet another big payday. He and Marquez have already gone 24 rounds with each other, rounds so close that ringside judges had trouble figuring out which fighter won.

But the first fight seven years ago was at 125 pounds. The second four years later was at 130 pounds.

This one will be for a piece of the welterweight title, though it will be at a catch weight of 144 pounds. It’s a weight Pacquiao has proven comfortable with over the last few years, but Marquez had no success the only time he got past 140 pounds in a lopsided loss to Floyd Mayweather Jr.

That’s the big reason Pacquiao is a 7-1 favorite in a pay-per-view fight that doesn’t figure to lack for action. “At 144 pounds it’s going to be different,” Pacquiao said. “I’ve improved my boxing and my power. Everything is going to be different.”

Pacquiao — who last lost in 2005 at 130 pounds — risks a 14-fight winning streak against Marquez, a Mexican who has held titles in three different weight classes. Once again he will carry the weight of the Philippines into the ring, and once again he will be fighting someone other than Mayweather.