Maidana stops Ortiz

Maidana improved to 26-1 with his 25th victory inside the distance, flattening Ortiz three times in the first two rounds and finishing him off 46 seconds into the sixth round, dropping the US prospect to 24-2 with one drawn.

Ukraine's Andreas Kotelnik, who won a split-decision victory over Maidana last February in Germany, remains the WBA world champion in the division.

He is set to defend that crown against Britain's Amir Khan next month at Manchester.

Elsewhere, undefeated Juan Manuel Lopez of Puerto Rico retained his WBO super bantamweight title when challenger Oliver Lontchi quit after the ninth round of their scheduled 12-round contest in Atlantic City.

Lopez, who improved to 26-0, knocked the Canadian-based Lontchi down with right-hand shots in the second and ninth rounds.

Lontchi, 26, could not recover from a crunching body blow and his corner threw in the towel before the 10th.

"Lontchi was real awkward and hard to fight," Lopez, 25, said. "Once I got the body shots in, it was over."

Cameroon-born Lontchi was behind 89-80 on all three cards.

WBA super featherweight champion Jorge Linares retained his title in Mexico with an eighth round stoppage win over Josafat Perez.

Linares, won was making his first title defence, sealed the victory when the one sided bout was ended after 1:42 of the eighth round

And Arthur Abraham made a successful 10th defence of his IBF middleweight title with a 10th round stoppage win over Mahir Oral in Berlin.

Abraham knocked down Oral in the fourth, sixth and 10th rounds as the unbeaten German secured a 30th consecutive professional win.