One particular instance of this sportsmanship came at the 2016 Hopman Cup. During the match against Lleyton Hewitt, Hewitt was serving to stay in the first set when his first serve at 30–0 was called out by the chair umpire. Prior to Hewitt hitting his second serve, Sock said: "That was in if you want to challenge it." The review showed the serve to be in, giving Hewitt the point.