Kei Nishikori ended Dominic Thiem's hopes of a home win at the Vienna Open to boost his ATP Finals chances, while Roger Federer stumbled into the Swiss Indoors Basel semis.

Thiem was aiming to become just the third Austrian to win the title in his homeland, but was completely outplayed by Nishikori in a 6-3 6-1 defeat.

Nishikori hit just 10 unforced errors in a match lasting under 70 minutes, and he now moves up to ninth in the ATP Race To London rankings ahead of John Isner and just a spot behind Thiem.

With three places remaining for the season-ending showpiece, Nishikori will look to further boost his chances by beating Mikhail Kukushkin in the semi-finals after the Kazakh needed three sets to defeat Marton Fucsovics.

Kevin Anderson is up to sixth in the London rankings. The big-serving South African was leading Borna Coric 7-6 (7-2) 1-2 when his opponent retired with a left-foot injury.

Fernando Verdasco is up next in the semi-finals, the veteran Spaniard having also benefitted from a retirement with Gael Monfils unable to complete their quarter-final.

In Switzerland, Federer moved a step closer to a ninth title albeit he was out of sorts in his 7-6 (7-1) 4-6 6-4 beating of Gilles Simon.

The 20-time grand slam champion needed two and a half hours to get the win and recorded a startling 60 unforced errors against the Frenchman.

Federer will look to rediscover his best against Daniil Medvedev after the Russian came through a see-saw battle with Stefanos Tsitsipas 6-4 3-6 6-3.

On the other side of the draw, second seed Alexander Zverev remains in hot form ahead of London.

The German made in six wins from seven matches with a 7-5 6-3 defeat of Roberto Bautista Agut, and will now face Marius Copil after the Romanian defeated Taylor Fritz 7-6 (8-6) 7-5.