ANAHEIM, California — Julio Cesar Chavez Jr. didn’t even show up until the fourth round against Jake Paul on Saturday at Honda Center. And even after he showed signs of life, he didn’t do much more than throw a few punches here and there, although he came on strong in the last few rounds.

Meanwhile, Paul did his job. He fought behind his jab, outworked Chavez by a mile and took everything his foe had to offer.

It wasn’t an easy fight for Paul in the end, but it was a clear victory and another step in what he hopes will lead him toward a world title shot. All three judges scored it for Paul: 99-91, 98-92 and 97-93.

It appeared in the first three rounds that Chavez’s handlers had forgotten to tell him he had a fight.

The 39-year-old, one-time middleweight titleholder, who is coming off a stint in rehab and has had a multitude of discipline issues, fought as if he were in survival mode for the first nine minutes. He did next to nothing.

And Paul (12-1, 7 KOs) took full advantage, setting up power shots with his jab, avoiding the few punches that Chavez threw and generally controlling everything that was happening in the ring.

The great Julio Cesar Chavez Sr., near his son’s corner, was so frustrated that he violently waved Junior toward his opponent and shook his head in disgust. He knew a good opportunity — a chance to set up more big fights — was slipping away.

Then, in Round 4, Chavez Jr. (54-7-1, 34 KOs) seemed to wake up. He began to stand his ground and throw punches, a number of them hard and some accurate.

He got Paul’s attention. The YouTuber-turned-boxer continued to outwork Chavez, but he had to be acutely aware of the dangers he suddenly faced. And he met the challenge with aplomb, at least until late in the fight.

Paul used his feet to try to keep his distance when Chavez went into attack mode. And when the Mexican got close, he often clinched. That prevented Chavez from causing serious damage.

Chavez’s best rounds were 9 and 10, when he threw punches with relative abandon and seemed to stun a tiring Paul on several occasions. He even raised his arms in triumph after Round 9, as if to say, “Yeah, I still have some fight in me.”

However, it was a classic too-little-too-late fate for Chavez, who couldn’t climb out of his early hole.

“He’s a tough, tough guy,” Paul said of Chavez. “He’s never been stopped, he’s a Mexican warrior. I respect Mexican warriors, I respect Mexico. I’m also a warrior. And I won tonight.”

Chavez, who admitted that he started too slowly, gave Paul credit afterward … to a point.

“He’s strong, a good boxer,” Chavez said in English. “The first four rounds … after that, I feel him getting tired. So I don’t think he’s ready for the champions, but he’s a good boxer.”

Paul was asked for his reaction to that comment.

“If I listened to anyone in life,” he said, “I wouldn’t be where I am today.”

Paul is dead set on facing world champions one day, including future Hall of Famer Canelo Alvarez.

“I thought I did great,” he said, “going 10 rounds with a former world champion who has never been stopped and was in there with Canelo Alvarez and all these guys. And I embarrassed him. Easy work.

“I want to be world champion. [Titleholder] Zurdo [Ramirez] looked slow tonight. That’s easy work, too. Badou Jack, Anthony Joshua. And Tommy [Fury, the only man to have beaten him] stop running.”

Who might be next?

“We’ll see,” Paul said. “We’ll go to the drawing board. There’s a long line of people waiting. Take a [expletive] ticket. I don’t care. I have time. I’m 28 years old. I’ll fight anyone, any time, any place.”