Canada's Felix Auger-Aliassime stunned Novak Djokovic 6-3 7-6(3) to put Team World within sight of their first-ever victory over Team Europe in the Laver Cup on Sunday.
Auger-Aliassime produced a masterful performance at a packed O2 Arena, holding off a Djokovic comeback in the second set to clinch Team World's second victory of the day.
Earlier, Auger-Aliassime and Jack Sock had come from a set down to beat Andy Murray and Matteo Berrettini 2-6 6-3 10-8.
Europe began the day with an 8-4 lead going into the last four matches of the weekend but with a win rewarded by three points on the final day, there was the potential for a big swing.
Serbian Djokovic had been imperious the previous evening on his return to action for the first time since winning Wimbledon in July to reach 21 Grand Slam titles.
He thrashed Frances Tiafoe and won doubles with Berrettini, but Auger-Aliassime carried the momentum of his doubles win into the singles.
The Canadian broke Djokovic's serve twice in the opening set and led 3-1 in the second before the former world number one, with Roger Federer supporting from the sidelines, began to find his range to drag the set into a tiebreaker.
But Djokovic's level dropped and Auger-Aliassime took advantage to record his first career win over the Serbian.
Tiafoe can give Team World an unassailable lead if he beats Stefanos Tsitsipas in the penultimate match.
If Greek Tsitsipas wins, everything will be decided in the final singles between Norway's Casper Ruud and American Taylor Fritz.
Should Team World, captained by John McEnroe, come out victorious it would be a massive turnaround after they lost 14-1 last year in Boston.
- IPL 2024 Retention Day Live Updates: Full list of retained, released, traded players; KL Rahul stays at Lucknow
- NBA roundup: 76ers end Thunder's six-game win streak
- China Masters 2023 final LIVE Score: Satwik-Chirag loses first game 19-21 to World no. 1 Liang-Chang
- Mohammed Shami, the good samaritan - shares video after helping road accident victim in Nainital
- Man United boss Ten Hag says season schedule tests players’ limits