By Steve Keating RICHMOND, Virginia (Reuters) - Slovakia's Peter Sagan emerged from the pack in the final climb up the cobbles and then powered his way to a spectacular victory at the road cycling world championships on Sunday. Long hailed as cycling's next big thing, Sagan hid in the bunch for most of the punishing 261.4km race, then lived up to his promise as he pulled away and held on for a three-second win over Australian Michael Matthews, according to unofficial results. As he crossed the finish line, Sagan lifted his hands in triumph, got off his bike and tossed it up the road. More...