Mexico's Juan Manuel Marquez made history on the weekend by defeating Filipino Manny Pacquiao by a spectacular sixth-round knockout in the decisive bout of the welterweight boxing competition.

Marquez, who was losing on points and receiving heavy punishment from Pacquiao seconds before the end of the sixth round at the MGM Grand Garden managed to land a brutal right on his rival's chin that sent the former world champion down on his face on the canvas and out cold.

Pacquiao's handlers needed several minutes to bring him back to consciousness while the 39-year-old Marquez stood up on the ropes to celebrate the victory with his frenzied fans in the arena, although his own face showed the effects of the Filipino's solid punching.

The 33-year-old Pacquiao had won his two earlier fights while another had been declared invalid.

The pair had fought to a draw in their first matchup back in 2004. The second time they fought was in 2008 and the third last year, and the Filipino won them both in controversial decisions after the full 12 rounds.

Marquez, who took home a purse of $10 million - to Pacquiao's $25 million - now has a record of 55-6-1, with 40 knockouts.

Pacquiao, who with his second consecutive defeat is in danger of losing his chance to fight unbeaten American Floyd Mayweather Jr., is now 54-5-2, with 38 knockouts. EFE