BASEL (AFP) - Roger Federer defied a 33-ace onslaught from Ivo Karlovic to reach his ninth straight final at the Swiss Indoors on Saturday with a 7-6 (7/3), 3-6, 6-3 victory.

The five-time hometown champion is now into his 11th career final at the St Jakobshalle, the event where he got his start in the sport two decades ago as a ballboy.

But it took a mighty effort from the 33-year-old world number two who achieved the break he needed in the third game of the final set.

Federer landed a return at the Croatian giant's feet which Karlovic netted to hand over three break points.

Karlovic then double-faulted as Federer broke for 2-1 to wild screams from a partisan crowd in excess of 9,000.

The end eventually came when the top seed leapt for an overhead smash for three match points.

One was all he needed, with a volley winner sealing a Sunday final with Belgian outsider David Goffin. The 28th-ranked Goffin ended the dream run of teenager Borna Coric, the conqueror of Rafael Nadal, 6-4, 3-6, 6-3 in his semi-final.