Jaime Munguia kept his WBA super middleweight title Saturday at The Venue in Riyadh, and for about ninety seconds of the sixth round it looked like he would not. Rafael Espinoza kept his WBO featherweight belt on a cut stoppage, and David Picasso lost his WBC Silver title to the Philippines’ Carl Jammes Martin, as the Mexico vs. The World undercard set up Canelo Alvarez’s challenge to WBC super middleweight champion Christian Mbilli.

Munguia (47-2, 35 KOs) beat Nikita Zon by unanimous decision, 116-112, 117-111 and 117-111, with Tony Weeks the referee, in his first defense of the belt. Zon (12-1-1, 10 KOs), the unbeaten Russian fighting outside his country for the first time, came to make it ugly. He pressed from the first bell, threw in flurries, leaned on Munguia in the clinches and roughed him up inside. Munguia answered the way he always has, with the body. He landed a left hook downstairs in the first, started finding combinations in the second and third, backed Zon up with a straight right hand in the fourth and wobbled him with a big shot late in the fifth. Through five rounds the champion was ahead and the challenger was starting to look like a man running out of ideas.

Then the sixth. Zon landed a left uppercut that caught Munguia clean and hurt him badly. Munguia’s legs went and he dropped to a knee; Weeks ruled it a slip. Zon did not wait for a ruling. He drove Munguia to the ropes and poured it on, hooks and uppercuts, with Munguia covering and the fight a punch or two from being stopped. Munguia stayed upright, took the storm, and somewhere in the last thirty seconds of the round started firing back. By the bell he was the one throwing. It was the round of the card to that point. MMA Fighting’s unofficial card scored it 10-8 for Zon without a knockdown; the official cards suggest at least two judges had it 10-9.

What Munguia did next is why he is still champion. He came out for the seventh behind the jab, went back to the body, and reestablished the range he had controlled before the sixth. Zon, who had emptied himself trying to finish it, slowed. Munguia won the seventh, eighth, ninth and tenth with cleaner work, and the last two rounds followed the same pattern, Zon still pressing but landing less, Munguia picking him off and investing downstairs. The fight went twelve. Munguia’s mandatory challenger is Bektemir Melikuziev.

Espinoza (29-0, 25 KOs) stopped late replacement Ricardo Blandon on a cut at 1:22 of the third round. Blandon (21-7, 14 KOs) had come in on a week’s notice after Lorenzo Parra failed a medical. Espinoza, who trained for the fight in Spain under Eddy Reynoso, his first camp outside Mexico, remains unbeaten.

The upset of the night came one fight earlier. Martin took a split decision from Picasso, 95-94, 96-93 and 94-95, to win the WBC Silver featherweight title. Picasso (32-2-1, 18 KOs), the Reynoso-trained Mexico City fighter who told Thursday’s press conference he was proud to be part of “one of the best boxing teams in the world,” had been the house fighter on a card built as Mexico against everyone else. Martin (29-0, 21 KOs) leaves Riyadh with the belt.

Reito Tsutsumi, the Japanese prospect and Ring Magazine ambassador, moved to 6-0 with six knockouts, stopping Raymundo Rojas Garcia at 2:27 of the second round.

On the prelims, Saudi Arabia’s Sultan Almohammed won every round against Erick Villegas, 60-54 and 59-55 twice, in front of his home crowd. Bek Nurmaganbet of Kazakhstan knocked out Marcos Vazquez at 2:57 of the first round. Carlos Emiliano Rojo stopped Flavius Biea at 1:38 of the fourth. Brayan Leon of Cuba outpointed Hector Aguirre 77-75, 78-74 and 78-74.

The card ran nine fights rather than the ten announced after Lindolfo Delgado’s vacant IBF junior welterweight title fight against Arthur Biyarslanov was lost to travel; Biyarslanov had already left Riyadh. DAZN’s announce team called the card from a studio rather than ringside, as Dan Rafael had reported ten days earlier. DAZN did not announce the arrangement before the broadcast.

Alvarez vs. Mbilli for the WBC super middleweight title follows in the main event.