The 20-year-old Nebraskan meets either Roger Federer of Switzerland for a place in Sunday's final.

Federer steamed past Schalken 6-3, 6-4, 6-4. Meanwhile, French 13th seed Sebastien Grosjean killed off British tenth seed Tim Henman's title dream on centre court on Thursday, winning their Wimbledon quarter-final encounter 7-6 (10/8), 3-6, 6-3, 6-4 in three hours exactly.

Grosjean now meets either Mark Philippoussis of Australia or German Alexander Popp in Friday's semis.

The unseeded 31-year-old Bjorkman pitted his serve-and-volley expertise, honed by years of top-level doubles playing, against the vast power and huge ground coverage of Roddick, the number five seed.

When play eventually began following a two and a half hour hold-up for rain, the pair swiftly exchanged service breaks, with the wily Swede, known as one of the best returners in the game, seemingly unfazed by Roddick's infamously brutal serves.

But once the American, who jointly holds the record for service speed at 149 miles per hour (238 kilometres per hour), got into the swing of his game and unleashed a string of aces, it rapidly became a one-sided affair.

Bjorkman continued rushing into the net but was repeatedly left standing as the man dubbed "A-Rod" swept low, powerful passes beyond his flailing racket.

The Swede, the reigning Wimbledon men's doubles title holder with Todd Woodbridge of Australia, is ranked only 79th in the world at singles, although he had beaten Roddick last year in the pair's only previous encounter.

He battled particularly desperately in the final set but was unable to deal with the speed and aggression of Roddick, who sealed the game with an exultant overhead smash.

With only Federer seeded higher than he is, the way nTow appears open for Roddick to begin fulfilling his massive promise.

Long hailed as the future of American tennis, Roddick has won only five minor titles to date.

At Wimbledon, where his powerful serve and quick feet are well suited to the speed of grass play, in two previous visits the US youngster had got no further than the third round.