Andy Roddick ripped apart Andre Agassi's baseline game and unloaded the fastest-ever serve on Saturday to reach the final of the Stella Artois Championships.

Roddick had never beaten the newly-crowned world number one in four previous attempts but under a cloudless west London sky, he was irrepressible and triumphed 6-1, 6-7, 7-6.

He will face Sebastien Grosjean in Sunday's Queen's Club final after the Frenchman brushed aside Britain's Tim Henman 6-3, 6-4.

"You try to serve fast out there," Roddick said, referring to the record 149 miles (239.8 km) per hour rocket he fired off in the second set.

"But not for the speed gun, to get it past the best returner of all time.

"It feels good to have won that. This week has been my best week for sure on grass."

The week will end even better for Roddick if he can overcome Grosjean to win his first grasscourt title at the 800,000 Euro ($939,800) event.

Henman, a runner-up here three of the last four years, could find no penetration on his serve and his dreams of becoming king at Queen's must wait another year.

However his performance here marks the first time in almost a year the Briton has won three matches in a row.

"I think it is a positive," Henman said. "Three wins in a row... that hasn't happened since last year's Wimbledon so this is a forward step.

"It is a positive, but it doesn't hide my disappointment. I wanted to get to the final again and win it this time."

Grosjean's verdict was clear cut. "I returned very well and Tim was not in good shape today," he said.

EXPLOSIVE STYLE

With second seed Agassi's former coach Brad Gilbert watching his new young charge from the stands, Roddick started his match in explosive style.

On the very first point, the 20-year-old walloped a 139 miles (223.7 km) per hour ace past his fellow American -- the first of 27 he hit during the match.

It was immediately clear Agassi would not be allowed to enjoy his latest stint as the oldest world number one -- the 33-year-old secured the honour by winning his quarter-final here on Friday.

Instead Roddick ran him ragged on the Queen's Club grass court, pumping winners left, right and centre to reel off the first set in just 20 minutes.

In the second game of the second set, the courtside speed gun showed Roddick to have hit the fastest serve on record, a 149 miles (239.8 km) per hour thunderbolt equalling the record set by Britain's Greg Rusedski in Indian Wells five years ago.

Agassi did return it, though, and managed to crack a smile about it afterwards.

"I got it back? Hey... sounds like I got some sort of record there too, then," he said.

But there was little to smile about on court for the winner of eight grand slam titles.

A POSITIVE

Railroaded in the first set, he dug his heels in and fought back in the second.

Roddick was unbending, but Agassi slammed winners of his own and levelled matters sneaking the second set tiebreak 7-5.

The elder American even managed a break in the third set but there was always a sense this would be Roddick's day and he broke back and forced a tiebreak.

The pair traded mini-breaks and Roddick fought off one match point at 6-5 down before clinching the win on his first match point 8-6 when Agassi fired a forehand long.

"The way he served and moved and the way I hit the ball, I didn't really deserve to win that match," Agassi said.

"But I gave myself chances... that is a positive."