BASEL: Radek Stepanek dimmed the qualifying hopes of Marin Cilic for a last-gasp spot in the ATP season-ending finals with a 4-6, 6-3, 6-3 upset win in the quarter-finals of the Swiss Indoors tournament on Friday.

Croatia's Cilic stands provisional 12th in the points race as he fights for one of a pair of slots remaining open in the eight-man World Tour Finals in London from November 22.

But after a promising start with a winning first set, Cilic fell victim to the crafty court-work which has made his 30-year-old Czech opponent such a threat.

The winner will await the result of the match between second seed Novak Djokovic of Serbia and Swiss sixth seed Stanislas Wawrinka.

At the top of the draw at the St Jakobshalle, two more Swiss - led by three-time champion and hometown hero Roger Federer - figure in the other quarter-finals.

Federer's good friend and occasional doubles partner Marco Chiudinelli was playing Frenchman Richard Gasquet while Federer was bringing a 17-match Basel win streak into his contest against Russian Evgeny Korolev.

Stepanek, playing Basel for the first time, completed his turnaround campaign in two hours, overcoming ten aces from Cilic and breaking on all four of his opportunities.

Cilic played the final last week in Vienna and was hoping for a running start this week heading into the wind-up Paris Masters from Sunday at the Bercy arena, last event of the ATP regular season.

Stepanek now stands 44-18 during the season in which he earned third and fourth ATP titles of his career in Brisbane and San Jose in the first two months of the year.

Cilic, 21, is still riding the best season of his young career, 46-20 with two titles.