Andy Murray sent down his fastest ever serve as he quickly dismissed Grigor Dimitrov to set up a quarter-final with Kei Nishikori at the US Open.
The second-seeded Scot recorded a 141mph serve as he exploited an error-strewn display from Dimitrov to complete a 6-1 6-2 6-2 win in New York.
Murray has reached the final of every Grand Slam tournament this year and will next face Nishikori, a man he has beaten in seven of their eight matches.
The Wimbledon champion had lost his last encounter with Dimitrov at the Miami Masters, but would dominate their latest meeting, breaking the Bulgarian's serve almost at will.
Dimitrov dumped a routine overhead volley into the net to offer an early 3-1 lead to Murray, who then reeled off the next six games in a row.
After collecting the first set, the Scot would surge 3-0 up in the second and briefly exchanged breaks with Dimitrov before serving out for a two-nil lead in the match.
Dimitrov had no answer to Murray's precise ground strokes which were finding the corners with pinpoint accuracy and the British No 1 added two more breaks to quicken his progress in the third.
A brief rain delay only kept Murray at bay for a few minutes and he returned to complete a dominant victory.
Asked about his fastest serve, Murray said: "I served one at 145 in San Jose, but the next day they recalibrated the gun, because it was completely wrong.
"But that is definitely the fastest serve that I have hit. I think the other fastest serve I hit was here at the US Open, around 138.
"But I've never hit over 140, so I think it was lucky. I only did it once, so I'm not expecting to do it again."