Britain's Andy Murray dropped just five games as he thrashed Bulgarian 22nd seed Grigor Dimitrov to reach the quarter-finals at the US Open.
Murray, the second seed, won 6-1 6-2 6-2 and goes on to face Japanese sixth seed Kei Nishikori in the last eight.
The Scot, 29, was below his best against Paolo Lorenzi in the previous round but superb against Dimitrov.
Juan Martin del Potro and Stan Wawrinka will meet in the other quarter-final in Murray's half of the draw.
Swiss third seed Wawrinka saw off Ukraine's Illya Marchenko 6-4 6-1 6-7 (5-7) 6-3, while Argentina's 2009 champion Del Potro led Dominic Thiem 6-3 3-2 when the Austrian retired with a knee injury.