Jack Sock is one fire in Perth at the Hopman Cup; he hasn't dropped a match in singles or doubles. On Thursday, the American also upped the hot shot ante during a 6-2, 6-2 win over Nick Kyrgios.

Suffice it to say that the label will stick after Day 1 of the Laver Cup. Sock, who is 6-16 in singles play this season but won the Wimbledon and US Open doubles titles (alongside Mike Bryan ...