The usually dominant Federer found the going tough against Srichaphan

The Swiss star, who is chasing his 11th title this year, beat Thai Paradorn Srichaphan 6-4 3-6 7-6 (7-5) in Basle.

Gonzalez powered into his third indoor final this season with a 6-4 6-4 victory over another Swiss player, Stanislas Wawrinka.

Federer defeated Gonzalez in last Sunday's Madrid Masters final.

He has never won his home event before - having lost finals to Thomas Enqvist and Tim Henman - but goes into Sunday's final with an 8-0 record over Gonzalez.

"(Federer) is the best player in the world and it's going to be really tough," Gonzalez said.

But the home favourite had to dig deep against Srichaphan, dropping his first set in 11 matches. And he was twice a mini-break down in the third-set tie-break before coming through.

"I obviously got a bit lucky in the end," Federer admitted after his 23rd straight win.

"You need that in a tie-breaker in the third set. I hung in there and am really excited to be in the final."

Gonzalez has been in superb form over the indoor season, reaching the final in Vienna, where he lost to Ivan Ljubicic, as well as the decider in Madrid.

His semi-final victory also boosts his chances of qualifying for next month's season-ending Masters Cup in Shanghai.