Marcos Maidana (31-2) stayed busy and scored a KO win over Russian Petr Petrov (29-3) in his native Argentina on Friday night. He dropped the loser with a sharp right in the fourth round 23 seconds in. Petrov earned his pay, in that he sought to give it back, but he is in a different skill class than Maidana. A left hook to the side dropped the loser, and he got up in time, but the ref looked in his eyes and halted the scrap with 21 seconds to go in the fourth.

Maidana, who had a scrap with Robert Guerrero cancelled because Guerrero hut his shoulder, had to earn his keep, as Petrov showed more than his resume promised. Next up for Maidana could well be another tussle with Erik Morales. Maidana won a majority decision over the game but severely faded Mexican in April, and with Morales' win over Pablo Cano last weekend, all signs point to a rematch.