 Katsidis' next opponent was Vicente Escobedo, whom he fought on 19 September at the MGM Grand Garden Arena in Las Vegas, as part of the undercard to Floyd Mayweather Jr. vs. Juan Manuel Márquez.The bout was for the WBO interim lightweight title (which had since been vacated by Joel Casamayor, some time following his victorious bout with Katsidis), with the winner receiving a guaranteed opportunity to face the WBO lightweight world champion.In a fight similar to the one with Amonsot two years prior, Katsidis and Escobedo exchanged hard punches for the full twelve rounds, with Katsidis surging forward aggressively and putting constant pressure on the retreating yet accurately counterpunching Escobedo.