Ruddock, 28, Finally Wears Down Page, 33 : Boxing: The fight is stopped after eighth round. Jackson stops Negron during first round.

Razor Ruddock, exposed as a one-punch fighter in two losses to Mike Tyson, stopped Greg Page after the eighth round Saturday night at the Mirage with that same single punch--a left hook.

However, Ruddock, 28, needed every ounce of his considerable strength to turn back the well-conditioned, 33-year-old Page. Ruddock never did knock Page off his feet.

Page, who was briefly the World Boxing Assn. champion in 1984 and 1985, could not walk a straight line back to his corner after the eighth round. Referee Joe Cortez followed him there, and stopped the fight.

Ruddock, who weighed 239 pounds, was making his first appearance since suffering a broken jaw in his decision loss to Tyson June 28. His new trainer, former heavyweight champion Floyd Patterson, couldn’t have been happy with what he saw.

Ruddock seemed to be visibly tired after three rounds, didn’t land a decent left jab and missed Page far more often than he hit him. In the fight’s early rounds, Ruddock often missed wildly with his left hand, like an over-eager amateur.

In fact, even when Page was defenseless on the ropes at the end of the eighth, Ruddock (26-3-1) was still missing him.

Julian Jackson, the World Boxing Council middleweight champion, didn’t miss much Saturday night. In the co-feature, he knocked out Ismael Negron with one punch, a left hook 50 seconds into the first round.

Page (34-10), 228, a 13-year-pro, showed a crowd of 3,032 how a superior boxer can make a superior puncher look inept. He tied up Ruddock inside often, eliminating Ruddock’s long-range attack, and slipped most of his long punches. Ruddock had Page hurt and dazed on the ropes in the opening minute of the fifth round, but Page eluded the lunging, 6-foot-3 Ruddock and survived the round.

Page, who offered little offense himself, seemed to be trying to pull Ruddock into the late rounds and perhaps finish him then or win a decision. After eight, the judges had Ruddock ahead by margins of 76-75 and 79-72 (twice). The Times card had Ruddock ahead, 78-73.

Jackson’s victory goes in the books as a TKO, but there wasn’t anything technical about it. Jackson’s hook landed flush on the jaw, snapping Negron’s head to the left. He collapsed immediately, landing on his back.

Jackson, called by some boxing’s best pure puncher, started his victory dance prematurely, running across the ring past the fallen Negron and standing on the bottom rope, waving to the crowd. Referee Mills Lane chased him there, retrieved him, and directed him to the opposite neutral corner.

Negron, meanwhile, was on his back during all this, and probably wouldn’t have beaten a 10-count. He arose shakily and Lane gave him a standing eight count before stopping the fight.

Jackson’s victory apparently set up a middleweight unification fight with the International Boxing Federation champion, James Toney.

Two other former fractional heavyweight champions, Bonecrusher Smith and Tony Tucker, both won on Saturday’s card.

Smith (32-9-1), 38, the WBA champion until Tyson beat him in 1987, scored a unanimous decision over Mark Wills (10-10-1) of Los Angeles. Smith has now won two fights since losing a Forum decision to Levi Billups November 4.

Tucker (42-1), who lost his International Boxing Federation title to Tyson in 1987, outclassed Kimmuel Odum (12-9), knocking him down twice during the second round. When Odum showed no eagerness to get up the second time, referee Carlos Padilla stopped the fight.

Bert Cooper (27-8), who came within a punch or two of upsetting heavyweight champion Evander Holyfield in Atlanta on Nov. 23, stopped Cecil Coffee in the second round Saturday night in his first appearance since then.

Cooper, who knocked Coffee down during the first round with an overhand right, finished him during the second with a right uppercut that not only knocked Coffee down, but broke his nose.