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Referee Kenny Bayless, left, directs Juan Manuel Marquez, right, to a corner as Manny Pacquiao sits on the mat after being knocked down by Marquez in the third round during a welterweight fight, Saturday, Dec. 8, 2012, in Las Vegas. Marquez knocked out Pacquiao in the sixth round to win their fourth bout. (AP Photo/Julie Jacobson)

Manny Pacquiao - Juan Manuel Marquez IV

December 10, 2012

Manny Pacquiao was dropped by a vicious right hand by longtime rival Juan Manuel Marquez in the sixth round as the two fought for the

fourth time at the MGM Grand Garden Arena in Las Vegas, Nev. on Saturday, Dec. 8, 2012.