Andy Roddick ripped apart Andre Agassi's baseline game and unloaded the fastest-ever serve to reach the final of the Stella Artois Championships.
Roddick had never beaten the newly-crowned world number one in four previous matches but, under a cloudless west London sky, he was irrepressible, winning 6-1 6-7 7-6.
After motoring through the first set in just 20 minutes, Roddick cranked up the power.
In the second game of the second set the courtside speed gun registered he had hit the fastest serve on record, a 149 miles (239.8 km) per hour thunderbolt equalling the mark made by Greg Rusedski in Indian Wells five years ago.
Agassi, the best returner in the game, was left powerless. But he stuck to his guns and levelled the match on a tiebreak.
Roddick, however, never flinched, crashing winners all over the court - including 27 aces - to clinch victory.
He will now face Sebastien Grosjean in Sunday's final after the Frenchman defeated home favourite Tim Henman in straight sets. Grosjean denied the British fans a chance to cheers on Henman in the final after disposing of the British number one 6-3 6-4.