Felix Auger-Aliassime moved Team World to within one win of capturing its first Laver Cup title on Sunday, when he upset Team Europe's Novak Djokovic 6-3, 7-6(3) to give his side a 10-8 lead, here.
The Canadian played aggressively throughout the one-hour, 35-minute clash to earn his first win against the Serbian. The 22-year-old hit his spots on serve, while he opened his shoulders to push the former World No. 1 back and triumph.
"I've been close a few times and in recent times to win against these great champions, so it feels great to get the win.Especially in front of the fans in this arena and for Team World," Auger-Aliassime said in his on-court interview.
If American Frances Tiafoe defeats Greek Stefanos Tsitsipas in the third match of the day, Team World will capture the title for the first time, with each clash on Sunday worth three points.
In the first match of the day, Auger-Aliassime and Sock edged Matteo Berrettini and Andy Murray 2-6, 6-3, 10-8.
In an entertaining battle at the O2 in London, the Canadian and American held their nerve when it mattered, finding first serves and deep returns in the Match Tie-break to secure their victory after one hour and 37 minutes.
Sock has now won four points for his side, having teamed with Tiafoe to defeat Roger Federer and Rafael Nadal in the Swiss star's final tour-level match on Friday night.
Captain Bjorn Borg is aiming to guide Team Europe to its fifth consecutive Laver Cup title against John McEnroe's Team World Sunday in the UK capital.