Former unified heavyweight champion Andy Ruiz Jr says he would be happy to give Chris Arreola a rematch after he was forced to recover from an early knockdown on his ring return.

Ruiz (34-2, 22 KOs), who stunningly ripped the IBF, WBA and WBO titles from Anthony Joshua in a huge upset, was boxing for the first time since losing an immediate rematch with the Briton in December 2019.

Veteran Arreola (38-7-1, 33 KOs) was widely viewed as a safe step back on the road to championship contention, as Ruiz fought with Canelo Alvarez's trainer Eddy Reynoso in his corner for the first time.

However, an overhand right from Arreola forced Mexico's first ever heavyweight champion to touch down in round two.

A thrilling shootout ensued in the third – Arreola again wobbling his foe with a thudding left hook – before Ruiz made use of his superior speed and boxing skills to close out a unanimous decision win by margins of 118-109 twice and 117-110.

Broadcaster Fox Sports tweeted after the bout to tout a potential matchup between Ruiz and fellow former champion Wilder.

That showdown has been previously discussed due to both men being under the Premier Boxing Champions promotional banner, but Ruiz acknowledged he might have unfinished business with Arreola, who was compromised by a left shoulder injury suffered in the eighth.

"I felt a little rusty but I kept going," he said afterwards. "If he wants to run it back then we can run it back.

"We can have Chris Arreola-Andy Ruiz II."

Ruiz was widely criticised for piling on excess weight before his rematch with Joshua and felt the need to turn over a new leaf by teaming up with Reynoso.

He weighed in almost 30lbs lighter for Saturday's fight in Carson than he did for the Joshua return, although he conceded complacency was still a factor as he diced with disaster.

"He caught me with that good, clean right hand," Ruiz said. "I dropped my guard a little bit and I was over confident.

"Chris Arreola is a veteran and a hard puncher. We did what we had to do and we got the victory.

"Remember, I was the lowest of the low and I had to start again at the bottom of the ladder. Now we can move on to the next one."