Lightweight  Maurício Ruffy kicked off the UFC 313 main card at T-Mobile Arena on Saturday with a Knockout of the Year candidate.   King Green , known for keeping his hands low, paid the price early in the opening round against the precision striker. In the early moments, Ruffy connected with a straight right hand that briefly staggered Green. Green remained in front of Ruffy and tried to keep him at distance with punches.   Ruffy remained patient and uncorked a spinning wheel kick that connected cleanly.