Australian teenager Lleyton Hewitt powered his way into the US Open semi-finals with a straight-sets victory over Frenchman Arnaud Clement.

The ninth seed rarely looked in trouble as he took control from the baseline, and also clocked up 18 aces.

Hewitt, 19, is the youngest semi-finalist since Pete Sampras made the last four a decade ago.

And he will now face Sampras after the American overcame Richard Krajicek in four sets.

"This is another step in my career," said Hewitt.

"It's fantastic to be up there with the boys who have made the finals of this tournament in the past."

"I have still got two matches to go to win the tournament. I'm playing better with each match I play."

Clement, the second-round conqueror of Andre Agassi, provided stiffer resistance in the third set.

But Hewitt saved a break point at 3-2 down and went on to take the match.

He had broken Clement twice in the first set - secured in just 29 minutes.

And Hewitt carried on the charge into the second set, winning the first game against serve.

With the match slipping away, Clement did draw back to 2-2 in that set but he was broken again in the seventh game as he went down 6-4.