Top-seeded Andy Murray overcame a slow start against Gilles Simon of France before winning 4-6 6-2 6-2 and advancing to his 13th quarter-final of the season at the ATP tournament in Vienna on Thursday.
The Scot, who improved to 16-2 against Simon in their career matches, clinched his 12th straight win of the season after taking back-to-back titles in Beijing and at the Shanghai Masters, where he beat Simon in the semifinals.
Murray broke Simon in the opening game of the match, but then struggled for rhythm as he dropped his first two service games.
The second-ranked Scot broke back when Simon missed a set point and failed to serve out the set at 5-3, but then lost his own serve for a third time.
Murray held off six break points early in the second set and finally looked to settle when he reeled off four straight games to level the match. From 2-2 in the final set, he did the same to close out the match.
Murray, who is 11-1 in quarterfinals this season, takes on John Isner for a place in Saturday's semifinals.
Earlier, Viktor Troicki advanced to his seventh quarterfinal of the season by defeating third-seeded Dominic Thiem 6-2 7-5.
Troicki, from Serbia, held serve throughout against the ninth-ranked Austrian but needed to save seven break points in the second set.
The 28th-ranked Troicki will next play Spain's David Ferrer, the defending champion, or Portugal's Joao Sousa.
Also, Jo-Wilfried Tsonga came back from 5-3 behind and saved a set point for Germany's Philipp Kohlschreiber in the opening set before beating him 7-6 (8-6) 6-2. The sixth-seeded Frenchman, who won the event five years ago, improved to 10-1 against Kohlschreiber.
Tsonga next plays Spain's Albert Ramos-Vinolas, who was a break down in the second set but won nine consecutive games to defeat Austria's Jurgen Melzer, 3-6 6-4 6-0.
