BEIJING—It was supposed to be a foregone conclusion that Russia’s powerful stable of figure skaters, including world champions in three of the four disciplines, would run away with the team gold medal at the Beijing Olympics. Nathan Chen and the rest of the Americans must have taken exception. The three-time world champ’s winning short program set the tone for Team USA on Friday, and everyone else followed suit. Madison Hubbell and Zachary Donohue won the rhythm dance with a season-best score, and Alexa Knierim and Brandon Frazier capped the first of three days of team competition with a personal-best short program. That left the Americans with 28 points, two ahead of the Russians and seven ahead of third-place China. “We can walk away with a medal for sure. What color? It’s hard to say,” Chen said. “But I have faith in my teammates, and I know they’re going to do …