Paris (AFP) - Gael Monfils clinched a maiden spot at the World Tour Finals on Thursday, securing the sixth place in the eight-man field in London after rival Dominic Thiem was defeated at the Vienna tournament.

Frenchman Monfils joins Novak Djokovic, Andy Murray, Stan Wawrinka, Milos Raonic and Kei Nishikori in the November 13-20 tournament.

"It feels great to qualify for the ATP Finals for the first time in my career," said the 30-year-old.

"It is a great way to finish my best season on the Tour," he said after a run of powerful form this season starting with a quarter-finals run at the Australian Open."

Thiem's hopes were hit by defeat to Viktor Troicki in Vienna while fellow London hopeful David Goffin also suffered a setback by losing to Juan Martin del Potro in Basel.

Marin Cilic stayed in the chase for the seventh spot at the World Tour Finals when he reached the quarter-finals of the Swiss Indoors with a 6-0, 7-6 (7-4) win over Pablo Carreno Busta.