In the TV opener on Showtime, we saw that age is just a number. But in the main event of a Showtime card on Saturday night, we saw that sometimes age does matter, that the younger guy sometimes just has an edge in speed, and strength, and stamina, and an old guy, much as he might try, cant do anything about it.

The younger guy in this case is Juan Manuel Lopez, who of course had his chin tested, but laid a hellacious amount of punishment on game but out of his weight class Rafael Marquez. Marquez, age 35, looked to be in danger of getting stopped through eight, but hed every so often come back with a swift left hook counter that threatened Lopez, age 27.

It was his right shoulder, though, which spelled his ultimate doom. He was unable to come out for the ninth, because of that shoulder, and with the TKO victory, Lopez looks ahead to a showdown in which he will not enter with a youth/weight class edge, against Yuriorkis Gamboa.

After the eighth, Marquez said, I cant move it, and his trainer asked him if he could continue. I cant go, he said.

Do you want to keep fighting? Do you want to keep fighting? the trainer asked. Ill keep going but its hurting. No, no, I cant go. I cant, I just cant go.

The trainer then pulled the plug. Rafa said hed like a rematch, and JuanMa agreed. Promoter Bob Arum said hed consider a rematch, but said JuanMa will next fight in PR, and then Gamboa, site TBD, in June.

Marquez (age 35; from Mexico City; 8-0 in Los Vegas; former 118 and 122 pound champion; 39-5 with 35 KOs entering) was 125 1/2, while the WBO featherweight champion Lopez (age 27; from Caguas, Puerto Rico; 29-0 with 26 KOs entering; ex junior feather champ) was also 125 1/2 pounds on Friday.

Lopez was the heel, it appeared, at the MGM as Marquez drew more cheers from the crowd during his ringwalk. But JuanMa looked loose and almost jovial as he readied for battle. Tony Weeks refereed the contest.

In the first, Marquez, who had to postpone the bout for a spell because he hurt his right thumb, was respectful of the kid. He sized him up, and Lopez too spent time scouting. They traded at the end of a warmup first.

In the third, Lopez hurt Marquez with a left; it sent him reeling. In the fourth, Marquez complained he got hit behind the head, and JuanMa ignored the protest, and advanced. Rafa had the look of a guy who wanted to fire, but whose body was betraying him. And then, he landed a left hook in close, and another, and a straight right. Lopez was unsteady, but shook the cobwebs. Then the ref took a point for hitting behind the head, but that gave Lopez extra time to clear his head. To me, it looked like Lopez still has issues with footwork, and balance, more than I mightve expected at this point. Maybe he always will…

In the fifth, we saw swelling under Marquez right eye. But his timing was on, and Lopez longer shots were taking too long to get there. Weeks glared at Lopez for holding and hitting. Hed have to be careful not to get another point deducted. He had a scratch under his right eye, nothing to be alarmed about. Marquez continued to bend down, dip his head down, and Lopez would sometimes pull it down more with his forearm.

In the sixth, Lopez went with the straight left, trying to maintain a smarter distance against the crafty Mexican, who was countering with hurtful hooks. It was a full-on JuanMa round.

In round seven, Lopez was bombs away, but Marquez exploded with his own left hook. JuanMa started using the uppercut more, with Marquez dipping that head. He was caught on the ropes, but got a break when Weeks again warned JuanMa. Your defense is a problem, Rafas trainer Daniel Zaragoza told him after. Indeed. Marquez looked to be in danger of succumbing to the punishment.

In round eight, JuanMa, looking muuuch fresher, much stronger, was having target practice, but then Marquez would land a straight right, or a counter hook. One doubted, heavily, wed see the twelfth. JuanMas pal Tito Trinidad yelled encouragement after the round.

He cheered loudly when he saw that Rafa wouldnt come out for the ninth.

Check back for David Avilas ringside report.