Nathan Chen suffered his first loss since the 2018 Pyeongchang Olympics on Saturday as he finished third at Skate America in Las Vegas, where fellow American Vincent Zhou won gold in the first Grand Prix event of the Olympic figure skating season. Chen, who was seeking a record-setting fifth consecutive Skate America title, was fourth after Friday’s short program and returned to score 186.48 points in the free skate for a 269.37 total that was not enough on a night that belonged to Zhou. Three-time reigning world champion Chen managed to deliver four cleanly landed quads but, with such high expectations for himself, left the ice shaking his head knowing it would not be enough to extend his reign with three skaters left to perform. During Friday’s skate, Chen fell on his opening quadruple Lutz and messed up a combination later in the program en route to a score of …