Team World have put a point on the scoreboard after Jack Sock and Kevin Anderson defeated Roger Federer and Novak Djokovic in the Laver Cup doubles on Friday.
Team Europe had been hoping for a clean sweep on the tournament’s first day but will head into day two with a 3-1 lead after Sock and Anderson beat the former world No.1s 6-7 (7-5) 6-3 10-6 in match four.
Earlier David Goffin, Kyle Edmund and Grigor Dimitrov gave Team Europe a 3-0 lead.
Belgian Goffin steered the defending champions with a 6-4 4-6 11-9 win over Argentine Diego Schwartzman.
Britain’s Edmund regained command in a tiebreaker before beating American Jack Sock while Grigor Dimitrov defeated Frances Tiafoe 6-1 6-4 at the United Centre.
Edmund broke Sock’s service to capture the first set 6-4. Sock, who came out to warm up wearing a Chicago Bulls jersey over his shirt, fought back and broke Edmund to go up 6-5 in the second set before serving it out as the crowd came alive.
Edmund then raced to a 7-2 lead in the 10-point tiebreaker that is used in the Laver Cup when the first two sets are split.
Dimitrov had 13 winners and two service breaks to win the first set 6-1, finishing it off with one of his five opening-set aces.
Tiafoe was a late replacement for Juan Martin del Potro on Team World.
The 20-year-old American played in the Davis Cup semi-finals last weekend in Croatia, losing the deciding match in five sets to Borna Coric.
He played much tougher in the second set on Friday against Dimitrov, getting a service break for 4-4 before Dimitrov broke back and served out the victory in a match that featured extended baseline rallies.