LOS ANGELES — A weapon that brought down Ricky Hatton more than 15 years ago would be brought back next week when Manny Pacquiao guns for the World Boxing Council welterweight crown in Las Vegas.

That particular tool — a left hand thrown with a slight arch that flattened the British bad boy in just two rounds in May 2009 — is being seen as the terminator.

It was on full display during Pacquiao’s spirited punch mitts session on Friday at the Wild Card Boxing Club where chief trainer Buboy Fernandez made it all public.

Of course, the blow is seen to land on the right spot without being set up and Fernandez swears Pacquiao will deliver it early.

“The instruction is for us to start strong and fast,” said Fernandez, who will assume the lead role in the corner.

“We will go to work early and press the attack immediately.”

The strategy is meant to force Barrios to fight back, a scenario Fernandez believes will give Pacquiao, 46, the best chance to inflict damage.

“Barrios is a slow starter, like a diesel engine,” Fernandez said.

While the 30-year-old WBC 147-pound champion needs time to get warmed up, Pacquiao is the exact opposite.

“We would go in there throwing punches. Just watch how many blows we are going to throw.”

The fast and furious start is the best way for Pacquiao to dethrone Barrios given the disparity in age.

The more the fight goes into the later rounds, the more chances Barrios will end up winning since he is the fresher and younger fighter.

“Two things,” blurted do-it-all American boxing man Sean Gibbons, who was watching from the sidelines.

“Stamina and reaction time.”

Questions abound whether Pacquiao, four years removed from his last professional bout, could still perform at a high level.

Based on what he has been showing the last two months, the speed is still there.

The power? It’s obvious.

The thunderous sounds the pad emits every time Pacquiao connects is proof it hasn’t left him.

But does Pacquiao still possess the reflexes needed to ward off an incoming asteroid?

Gibbons swears the sparring sessions have given the team an insight of what’s about to come.

It’s true that there were a few times when Pacquiao got smacked but the occasions where he got the better of his sparmates far outnumber them.

“It’s amazing that at this stage, you still see him do these things,” Gibbons said, laughing at how the Hall of Famer clearly underlined the vast difference between mere mortals “like us” and demigods.

On fight night, Pacquiao will attempt to prove his critics wrong one more time.

And if succeeds, most likely, it will be because of that left hand of his that sent Hatton to dreamland.