Mansour should win unless he gasses himself out or gets caught with a big shot. He's far fresher than Briggs and has fought at a far higher level these past few years. He's also a vicious KO puncher. Remember what he did to Fred Kassi.
Mansour should win. Briggs is shot all to pieces and has only a puncher's chance and not that big of one. Mansour is old but fights surprisingly well for his age.