The second-seeded Murray, who had a bye in the first round, dropped serve while leading 3-2 in the second set but held off five more break chances for Pospisil. The Canadian had 27 aces in his first-round win over German Daniel Brands but just three against Murray.
“It was a tricky match to start with. He serves well and is a quick mover,” Murray said. “It was hard. It was the first time I played indoors since Rotterdam, which was seven, eight months ago. And it’s always different to play indoors. The match could’ve definitely been a lot closer.”
Murray decided only last Friday to accept a wild card as he is chasing points in order to qualify for the ATP Finals in London next month.
“Hopefully, I can improve for my next game,” the Scot added after his 470th career win. He joined Fabrice Santoro in 50th place on the Open era win list.
Murray next plays Jan- Lennard Struff, of Germany, who won the last seven points in the third-set tiebreaker to beat Sergiy Stakhovsky, of Ukraine, 7-6 (6), 2-6, 7-6 (3).
David Ferrer advanced to his 15th quarter-final of the season after defeating Tobias Kamke of Germany 7-5, 6-1. The fifth-ranked Ferrer, the top seed, avoided service breaks and converted his second match point with a forehand winner. He will play No 6 Ivo Karlovic, of Croatia, in the quarter-finals. The Spaniard needs to reach Sunday’s final to improve his chances of qualifying for the ATP Finals.
Earlier, Thomaz Bellucci, of Brazil, rallied to beat the 2004 champion, No 3 Feliciano Lopez, 6-7 (9), 6-1, 6-4. Lopez, who was ranked a career-high 14th after beating Rafael Nadal on his way to the Shanghai semi-finals last week, lost eight straight games from 1-1 in the second. The Spaniard also lost 19 points in a row.
Bellucci will meet Serbian Viktor Troicki, who reached his third quarter-final since returning from a doping ban in July by beating No 5 Lukas Rosol, of the Czech Republic, 6-3, 6-2.
Also, Benjamin Becker, of Germany, defeated last year’s finalist, Robin Haase, of the Netherlands, 6-3, 6-3. He lined up a quarter-final against compatriot Philipp Kohlschreiber.
At the Stockholm Open in Sweden, meanwhile, top-seed and former champion Tomas Berdych beat Dustin Brown of Germany 7-5, 6-3 to reach the quarter-finals, where he will play Romanian Marius Copil, who beat Pierre-Hugues Herbert of France 6-4, 6-3.