Andy Murray moved a step closer to qualification for the World Tour Finals in London by defeating Germany's Jan-Lennard Struff at the Vienna Open.
The 27-year-old Briton continued his pursuit of ranking points with a 6-2 7-5 win to set up a semi-final with Serbian Viktor Troicki on Saturday.
Murray, 10th in the race to London, is competing in Austria alongside Spain's David Ferrer, who is ninth.
The top eight players qualify for the season-ending tournament.
Should Murray win the Vienna Open, he will move into eighth place with tournaments in Valencia and Paris to come.
After twice breaking serve on his way to comfortably claiming the first set, Murray found himself 3-1 down in the second before rallying to a 6-5 lead and sealing the win with an ace on his second serve.
"I had to play well to win and fight to get through," said Murray. "My game was more consistent than in the previous round. I was able to change up the rhythm."
Ferrer, 32, set up a semi-final against Philipp Kohlschreiber by defeating Croatian world number 29 Ivo Karlovic 7-6 (7-5) 6-4.
|Six players are chasing the three remaining places for the ATP World Tour Finals (Cilic sixth in race but qualifies as he won US Open)|
|Player and position||Points||Tournaments played|
|5 Kei Nishikori (Jap)||4,265||20|
|7 Tomas Berdych (Cze)||3,945||20|
|8 Milos Raonic (Can)||3,750||17|
|9 David Ferrer (Sp)||3,715||22|
|10 Andy Murray (GB)||3,655||18|
|11 Grigor Dimitrov (Bul)||3,450||18|
Germany's Kohlschreiber defeated countryman Benjamin Becker 6-4 7-6 (7-4), while world number 137 Troicki defeated Brazilian Thomaz Bellucci 7-6 (7-4) 6-7 (2-7) 6-2 to earn his spot in the last four.
Novak Djokovic, Roger Federer, Rafael Nadal, Stan Wawrinka and US Open champion Marin Cilic have already secured their places in the World Tour Finals, to be held from 9-16 November at the O2 Arena.
Bulgaria's Grigor Dmitrov and Czech Thomas Berdych, who both reached the Stockholm Open semi-finals on Friday, are also in contention for a place.
Dmitrov defeated Jack Sock of the United States 5-7 6-4 6-3 and will next play Australian Bernard Tomic, while Berdych beat Romania's Marius Copil 6-2 6-2 and faces German Matthias Bachinger.
Murray's chances of qualifying for the World Tour Finals were boosted by defeat for Wimbledon semi-finalist Milos Raonic of Canada in round two of the Kremlin Cup in Moscow on Thursday.