ATLANTIC CITY, N.J. --Spinks Jinx indeed.

First it was Leon, beating Muhammad Ali. Then it was Michael, upsetting Larry Holmes. Tonight it was unheralded Cory Spinks, who added the WBC and WBA welterweight belts to his IBF crown with a majority 12-round decision over boxing's latest poster child, Ricardo Mayorga, in one of eight title bouts on the Don King mega card at Boardwalk Hall, a holiday spectacular that put to shame anything Radio City Hall could come with.

Scores were 117-110, 114-112, and 114-114 for Spinks, who used a disciplined defensive attack and enough offensive retorts to befuddle Mayorga, who was looking at a possible Fighter of the Year award until tonight's disaster.

"I have been hit hard all my life," said Spinks. "I kept my head and did what I had to do -- box."

Mayorga (25-4-1, 22 KOs) was his usual carefree self as the bout commenced, mugging to the crowd at every opportunity. But what the cheering throng may have missed was that Spinks (32-2, 11 KOs) was making the WBA/WBC champ miss on every occasion in the opening frame.

The Dave Kingman impression by Mayorga continued in round two, and in response, Spinks started to pepper his foe with pesky jabs and left hands, frustrating the Nicaraguan, who was warned by referee Tony Orlando for foul tactics.

Finally getting on the board in the third with a solid left hook, Mayorga stepped up his offensive pace, but Spinks fought back undaunted. And though Mayorga laughed unhurt, the damage on the scorecards was being done, even as "El Matador" drilled Spinks with -- what else? -- a hook at the bell.

Spinks kept Mayorga turning in the fourth, and the frustrated favorite's rushes started to become wilder and more amateurish as the round wore on. Even when he was able to land cleanly, Spinks took each shot in stride and made sure to finish each exchange.

Calling Spinks to him to stand and fight, Mayorga was pulling all his tricks out of the bag to get "The Next Generation" into a brawl. Spinks calmly boxed away, but moments later got nailed and bloodied by Mayorga. Showing the fighting spirit epitomized by his forefathers, Spinks took each blow and came back firing. And if there was any question about the "Spinks Jinx" (you'll see this again), a point deduction from Mayorga for hitting after the bell nullified any advantage he may have enjoyed in the fifth.

The pace slowed in the sixth, allowing Spinks to pick his shots -- not heavy blows, but pesky ones -- shots that left Mayorga following impotently as he tried to land a haymaker.

Mayorga got closer in the seventh and eighth, doing some sloppy but effective work on the inside (where Spinks' speed and boxing skills were not a factor), and even hurting Spinks briefly in the eighth.

Buoyed by his good fortune, Mayorga came out confidently for the ninth, but Spinks got back into the pattern that brought him success earlier in the bout -- jab, duck, turn; jab, duck, turn -- forcing Mayorga to resort to holding Spinks' head under as he tried to chop down with a right hand.

Spinks opened up his offensive attack in the tenth, and the pro-Mayorga crowd started to "ooh" and "aah" with every Spinks flurry. To top it off, as the two battled it out to end the round, it was Spinks leering at Mayorga when the bell rang.

In the eleventh, the news got worse for Mayorga as he lost another point for hitting behind the head, and his frustration left him flailing wildly in the twelfth, trying to come up with a title-saving haymaker as Spinks boxed cautiously and held whenever Mayorga got too close. Even a shot to the ribs that dropped Spinks legitimately in the final minute went unrewarded by Orlando, another symptom of the "Spinks Jinx."

"I absolutely won the fight," said Mayorga. "The referee was not on my side. He didn't have to take points away from me. If it wasn't for the referee I would have won the fight. He never really hurt me and none of his punches landed clean. I don't know what the judges were looking at."