The Swiss rider held on through a tough final climb to battle in the stage 1 sprint in a fast finish on rain-slicked roads. He handily out-gunned Diego Ulissi (UAE Team Emirates) and Jesus Herrada (Movistar) to cross the line first.
Team Sky's Chris Froome got involved in the finish as well, claiming fifth.
Trek-Segafredo's Fabio Felline finished safely in the pack to hold on to his spot atop the overall race leader board.
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