Hector (Macho) Camacho piled up points with superior hand speed and survived near-knockdowns in the fifth and 11th rounds tonight to defend his World Boxing Council lightweight title with a 12-round split decision over former champion Edwin (Chapo) Rosario.

Earlier in the card at Madison Square Garden, unbeaten heavyweight Mike Tyson knocked down Reggie Gross twice and stopped him in the first round of a scheduled 10-round fight.

Camacho (30-0) was in control for most of the fight, but endured some of the scariest moments of his seven-year pro career. He had things go his way until a right from Rosario (23-2) sent him reeling into the ropes and drew blood from his left eye late in the fourth round. In the fifth, Rosario bloodied Camacho's nose.

"To be honest, this is the first fight I ever got hit consistently hard," Camacho said. "That guy was hammering me with things I've never been hammered with before."

For 20-year-old Tyson, of Catskill, N.Y., it was the 20th knockout in 22 victories. In his two previous fights, he had gone the distance, winning 10-round decisions over James (Quick) Tillis and Mitch Green. Gross, of Baltimore, is 18-5.

Earlier, Julio Cesar Chavez, 23, of Mexico stopped Refugio Rojas in the seventh round to retain his WBC super featherweight title.