LOS ANGELES — Andy Ruiz landed just enough big punches on Luis Ortiz to make up for his mistakes and caution in a narrow victory that kept him on the path to a chance to become the heavyweight champion again.

Ruiz knocked down Ortiz three times on the way to a victory by unanimous decision Sunday night.

Former three-division world champion Abner Mares also fought to a majority draw with Miguel Flores in Mares’ return from a four-year ring absence on the pay-per-view undercard. Lightweight Isaac “Pitbull” Cruz then stopped Eduardo Ramirez in the second round with two vicious knockdowns.

In the main event, Ruiz (35-2, 22 KOs) grinded out a decision over Ortiz (33-3), a two-time world title challenger. The Southern California native knocked down the 43-year-old Ortiz twice in the second round and again in the seventh, but his Cuban opponent battled through a badly swollen left eye and punched more accurately during long stretches of relative inactivity for both fighters.

“I worked so hard for this fight, because I knew he’s a warrior and he hits hard,” Ruiz said. “I thought I did a beautiful job boxing him around and handling his pressure.”

The judges scored the bout 114-111, 114-111 and 113-112 for Ruiz. The Associated Press also had Ruiz 114-111, with the knockdowns making the difference.

Ruiz pulled off one of the bigger upsets in recent heavyweight history when he took Anthony Joshua’s three championship belts in 2019, only to lose them back to his British opponent six months later. Ruiz had fought just once since, but he rededicated himself to training with hopes of getting another shot at the belts.

“I do not want to be waiting,” Ruiz said. “I want to fight at least three or four times a year. I’m hungry, man. I want to be a champion again.”

After entering the ring in a blue-and-gold robe and trunks featuring the Super Bowl champion Los Angeles Rams’ colors and helmet horns, Ruiz abruptly floored Ortiz early in the second round with a short right hand. Ortiz wobbled to his feet and soon slipped back down while trying to clinch with Ruiz, but he made it to the bell.

“To everyone who said that I’m old, I gave you a war today,” Ortiz said. “I would want a rematch. The eye wasn’t a problem for me. Do you think I’m done after the way I fought? Do the people think I’m done? I don’t think so.”

Neither fighter threw much or risked much in the next four rounds, and the crowd that loudly backed Ruiz grumbled its displeasure. But Ruiz connected again late in the seventh, staggering Ortiz before sending him to the canvas with a right to the top of the head.

“It was very difficult,” Ruiz said. “I was waiting for him to load up, and countering him when he did. It was a blessing we were able to be successful.”

Earlier, Cruz (24-2-1, 17 KOs) made his case for a rematch with Gervonta “Tank” Davis with his two-round demolition of Ramirez, first knocking him down face-first with a left hook to the jaw before finishing him with a combination in the corner.

Davis, who narrowly beat Cruz by decision last December, smiled as he watched the bout from ringside amid chants of: “We want Tank!” from Cruz’s fans.

Mares (31-3-2) hadn’t fought since his second loss to Leo Santa Cruz in June 2018. He recovered from surgery on a detached retina shortly before the start of the coronavirus pandemic, and his ring absence stretched on while he landed a commentary job with Showtime.

But Mares eventually decided he had to return, and he looked quite sharp early against Flores (25-4-1) with a series of big right hands that rocked his opponent. Mares tired in the second half, but won 96-94 on one judge’s card. The other two scored it 95-95.

“Obviously it had been over four years, so I was a little off with my timing, and a little sluggish,” Mares said. “But I felt good, and I thought I was landing the more powerful shots. I definitely felt like I won.”

The pay-per-view card opened with an enormous upset: Edwin De Los Santos, a Dominican lightweight filling in as a late replacement opponent, battered previously unbeaten Mexican prospect José Valenzuela for a third-round stoppage victory. De Los Santos was only added to the card Wednesday when Jezreel Corrales couldn’t secure a travel visa from Panama.