Got my money on the tough and gritty old man by KO! I like Joyce, but he's too easy to hit for Ortiz not to land a big shot.
Ortiz is obviously a very dangerous fighter, his ability to land a devastating counter makes him a threat to anyone. But having said that Joyce showed vs Dubois he can stick behind his quality jab and move and not just walk in and be countered like he has done vs lesser opponents. Joyce also has a solid chin, he may not be so easy to put away even if Ortiz does land a bomb. Ortiz is a plodder, he needs fighters to come to him to look good, so he can set his feet and counter, he'll struggle with the movement and jab of Joyce and once he tires like he did twice vs Wilder he'll be vulnerable himself and once Joyce feels the old man tire he'll turn up the pace and get Ortiz out of there.
Mike Perez and Artur Szpilka were undefeated and top 20 when Jennings beat them. Jennings was ranked at No. 7 when Ortiz beat him too.
I think it's more than debatable as to whether Ortiz is a step up over Dubois. Ortiz is as old as the dirt your house is built upon. He's hardly beaten anybody who's any good. Dubois hasn't either, but at least he's young. He'll have a better career than Ortiz. To answer the question, Joyce easily beats Ortiz - obviously.
Ortiz is a 5-6 round fighter these days and he gasses horribly after that point. With every passing year he gets further away from his 50th birthday. Joyce is a relentless truck, who has great stamina and output. Joyce by late stoppage.
Joyce eats big shots for breakfast. Even a prime Ortiz "way back in the day" has nothing in his arsenal that can deter the juggernaut. Thump thump thump forward forward forward. Joyce walks through Ortiz taking everything he has to offer, without as much as a flinch. Just a smile followed by another jab. Maybe a 16lb long shaft keying hammer would help Ortiz, but thats debatable.
May I ask which rankings you are using for the historical record? I'm going off the PBO rankings, as they are algorithm based. They had Perez at 21and Spilka at 23, and Dimitrenko at 22. But it doesn't matter much, as I was wrong anyway. Jennings was also coming off a loss when he fought Joyce. I thought he fought Joyce then Rivas. It was the other way around. Which definitely changes things.
Taking Ortiz from 4 years ago against Joyce from now I’d favour him to take a tough and hard fought decision, but I do see the argument for Joyce at the stage they are both at now. Ortiz as a live underdog, but I’d slightly favour Joyce coming on strong down the stretch.