Team Europe closed in on victory in the Laver Cup after building a commanding 11-1 lead over Team World in Boston.
Stefanos Tsitsipas, Alexander Zverev and US Open champion Daniil Medvedev won their singles matches to extend Team Europe's lead from 3-1 to 9-1.
Andrey Rublev and Tsitsipas then claimed victory in their doubles match as Team World failed to register a win on the second day.
Team Europe need one win on Sunday to retain the Laver Cup.
The contest is the fourth edition of the event, which sees six men's players from Team Europe and Team World play a series of singles and doubles matches.