Saul Alvarez knocks out Jose Miguel Cotto in undercard bout

Reporting from Las Vegas -- The 16 men on Saturday’s eight-bout undercard to Mayweather-Mosley were fighting for a lot less in both purse and prestige. But they didn’t take their job any less seriously.

The most compelling of the preliminary matchups was the last one, a renewal of boxing’s longstanding Mexico-Puerto Rico rivalry and a slugfest in which neither Saul Alvarez of Guadalajara nor Jose Miguel Cotto, a Puerto Rican Olympian and the elder brother of former world champion Miguel Cotto, gave an inch.

But after a difficult first round in which he was nearly knocked down in his own corner, the 19-year-old Alvarez (32-0-1 with 23 knockouts), fighting at 150 pounds, stormed back to knock an exhausted Cotto (31-2-1) out with less than 10 seconds left in the ninth round.

Earlier in the night, southpaw Daniel Ponce De Leon (39-2, 32 KOs), a former Mexican Olympian, held off late-starting Cornelius Lock (19-5-1, 12 KOs), a former U.S. amateur champion from Detroit, to win a unanimous decision in a 10-round featherweight bout.

In a bizarre welterweight bout that lasted less two minutes, Said Quali, a 29-year-old Moroccan fighter out of Las Vegas, climbed off the ropes to knock out once-beaten Hector Saldivia of Argentina.

Quali (27-3, 19 KOs) was on the canvas 14 seconds into the fight. And seconds after climbing to his feet, he was pinned against the ropes and appeared defenseless.

But he escaped, then knocked Saldivia down with a wild left seconds later. Saldivia, who came in 31-1 with 24 knockouts, still appeared groggy after getting up and Quali quickly took advantage, knocking him down to one knee with a straight right, just the 13th punch he threw.

When Saldivia got up a second time, he went to his corner and referee Russell Mora stopped the bout with 1:53 left in the round.

Jesse Vargas of Las Vegas ran his record to 10-0 by staggering Arturo Morua (25-14-1) of Guadalajara with a left-right combination, forcing referee Tony Weeks to halt their welterweight fight at 1:20 of the sixth round.

In a junior welterweight fight that went 10 rounds, unbeaten Eloy Perez (17-0-2) of Salinas, Calif., won a majority decision over Gilberto Leon (23-8-2) of Mexicali, helped in part by a right uppercut that knocked Leon down late in the third round. And in a lively eight-round super middleweight matchup, Dion Savage of Flint, Mich., ran his record to 8-0 with a unanimous decision over a game Tommie Speller (5-4) of Philadelphia.

In the first fight of the day, unbeatean Luis Ramos Jr. (15-0, 8 KOs) of Santa Ana made quick work of Allen Litzau, knocking him to the canvas early in the second round, then popping him again when he got up. That led referee Mora to stop that bout, a junior welterweight battle, 55 seconds into the round.

Litzau (13-5, 7 KOs), of St. Paul, Minn., loudly protested the decision before storming out of the ring alone without acknowledging Ramos.

And in a junior welterweight bout that matched a pair of Las Vegas fighters making their professional debuts, Daniel Reece won a unanimous-decision victory over Angel Soto.

kevin.baxter@latimes.com