Murray beat Paul-Henri Mathieu in round one
Andy Murray defeated Spaniard Albert Montanes 7-5 6-3 to reach the quarter-finals of the China Open in Beijing.
The British number one, seeded second, will play either Ivan Ljubicic or Alexandr Dolgopolov next.
Third seed Robin Soderling beat Nicolas Almagro 7-5 4-6 6-3 to set up a clash with eighth seed David Ferrer, who beat Lu Yen-hsun 6-3 3-6 6-1.
In the women's draw Caroline Wozniacki will become world number one if she beats Petra Kvitova later on Thursday.
Earlier on Thursday, Serbia's Ana Ivanovic beat Russian seventh seed Elena Dementieva 7-6 (7-2) 7-6 (7-4) while Anastasija Sevastova of Latvia had a walkover against 13th seed Nadia Petrova of Russia.
Murray, who needed only 74 minutes to overcome French qualifier Paul-Henri Mathieu 6-2 6-3 in his first-round match on Tuesday, has now played Montanes four times and is yet to concede a set.
The first four games went with serve - Murray winning both of his to love - but the Scot was stunned in game five when Montanes capitalised on his fourth break point with a stunning cross-court backhand winner.
Murray, 23, squandered a gilt-edged break-back opportunity at 3-4 and found himself serving to stay in the set in the following game, but held to force his 29-year-old opponent to serve it out.
However, the errors crept in for Montanes and a forehand winner from Murray at break point proved decisive and got the match back on serve.
Murray breezed through his next service game and then broke his rival for a second time to secure the set 7-5.
Montanes won the first two games of the second set before Murray reeled off five straight games to put himself firmly in control.