Michael Spinks needed six minutes of play and 62 seconds of work today to defend his undisputed light heavyweight title against David Sears.

After losing the first two rounds on two of the judges' cards, Spinks decked Sears with an overhand right early in the third round and pounded away with both hands until referee Larry Hazzard stopped the fight at 1:02 of the round.

"I knew I could hit him with the right from the start," Spinks said after his ninth title defense.

Spinks improved to 26-0 with 18 knockouts in his first fight in nearly a year. He last defended his 175-pound title by winning a 12-round decision over Eddie Davis on Feb. 25, 1984.

Sears, the World Boxing Association's second-ranked contender, fell to 16-1-1.

Spinks, who is considering a move up to the heavyweights, surprisingly weighed in at 170 1/2. Sears, who weighed 174 1/4, thought he could take advantage of his superior weight and Spinks' habit of starting slowly.

"He did surprise me with his strength, especially since he came in so light," Sears said.

Spinks needed just two rounds to size up his gangly opponent. At the start of the third round, Sears began to throw a left hook but Spinks beat him to the mark with an overhand right and Sears went sprawling face first to the canvas. Sears took a six-count, then Spinks sprinted across the ring and pounded him in a neutral corner.

Using left hooks and right uppercuts, Spinks peppered the flailing Sears to the head until Hazzard broke the fighters before letting the action continue. Spinks resumed his attack and, after a brief two-handed flurry to the head, Hazzard separated the fighters again and stopped the bout.

"He surprised people at how devastating a puncher he is at the weight of 170 1/2," Spinks' promoter, Butch Lewis, said.

"The lighter, the faster," Spinks said. "I haven't been that low in a long time. I was incredibly right.