The 22-year-old Swiss star blasted 12 aces to defeat top-ranked US Open champion Andy Roddick 7-6, 6-2 while Agassi began 90 minutes late due to rain then struck like lightning to eliminate Rainer Schuettler 5-7, 6-0, 6-4.

Federer had lost his first three career matches against Agassi but beat the Australian Open champion 6-7, 6-3, 7-6 on Monday in a round-robin match at the season-ending 3.75 million-dollar showdown of 2003's top players.

"Both players took something out of that match and in the final we will try and do better," Federer said.

"I prefer my position. He had to work really hard to get to the final. I think that's more advantage (for me) than disadvantage."

Beating Agassi in Sunday's best-of-five final would bring Federer a year-end number two ranking, an ATP-best seventh title of 2003 and 1.5 million dollars as only the fourth man with an unbeaten run in the ATP year-end event.

"Roger doesn't allow you to just lay off shots. He has firepower from a lot of different points," Agassi said. "The difference is how you play those real crucial points."

Federer beat French Open champion Juan Carlos Ferrero on Friday so improving to 5-1 against Roddick gave him a one-week sweep of the 2003 Slam champions.

"It's always nice to beat such great players," Federer said.

"I had a bad record against top-10 players this year. It's nice to polish that up."

Federer defeated Roddick in a Wimbledon semi-final and was just as dominant here four months later against the 21-year-old American, now 1-2 since sealing year-end number one honors.

"He kicked my ass then and he kicked my ass tonight," Roddick said.

"I'm upset I lost but I'm relieved the year is over. I'm going to chill out for a while."

Relatively easy triumphs could help Federer for the final, Roddick said.

"Roger hasn't too many tough matches so that could be a factor in his favour in a best-of-five final," Roddick said. "On the other hand I don't know if I remember seeing Andre tired before. That might be a moot point."

Facing so strong a foe as Agassi again so soon after a hard-fought victory is unusual for Federer.

"It's kind of a strange feeling. Sometimes we get that in the ATP but not usually against such a tough player," Federer said.

"He's going to make you work. It's my last match of the year. I'm going to give it everything I have."

Federer won his first set in 38 minutes, finishing Roddick with his eighth ace, then broke with a backhand winner for a 3-2 lead in the second set and again with a forehand winner for a 5-2 edge before ending it after 62 minutes.

"He played super out there," Roddick said.

"I just felt like he was a step faster than me. He just outplayed me. That's the bottom line."

Eight-time Grand Slam champion Agassi, who won the ATP year-end event in 1990 and lost in the 1999 and 2000 finals, is the event's oldest semifinalist since Arthur Ashe in 1978 and could become its oldest champion.

"I've spent the better part of my career being older," Agassi said.

"My age is irrelevant to me when I'm on the court."

Agassi has shown top form despite coming here after a two-month layoff since losing to Ferrero in the US Open semifinals, a break during which his wife, Steffi Graf, gave birth to their first daughter, Jaz.

"It has turned out to be a good decision (to rest), one I should have made a lot more often the past few years," Agassi said.

"There have been a lot of years I have come to this tournament far more spent than prepared."

Agassi, now 3-1 against sixth-ranked Schuettler, overwhlemed the German 6-2, 6-2, 6-1 in January's Australian Open final, the shortest Aussie final since 1926 and the biggest rout in a Grand Slam final in nearly 19 years.

Schuettler won the first set's only break point to end it, but fifth-ranked Agassi answered by winning the next eight games.

"I picked up the pace of my shots," Agassi said.

"I felt like I had no choice but to step up the level on my shots and he came down a notch."

Schuettler broke back to level at 2-2 but Agassi broke back in the next game and held out to win after two hours and eight minutes.

"He stepped on the gas a little bit. That's why he's a great player," said Schuettler.

"He knows when he has to play one step better and he did. If you give him a little bit of space, he just takes over."