The Serbian player is one place outside reaching the ATP World Tour Finals in London with Jo-Wilfried Tsonga occupying the eighth and final spot.
The top seed made clear his intentions in his second-round clash in the Thai capital, dominating on his serve with eight aces as he went through 6-4 6-4 in one hour and 37 minutes.
World number 45 Gael Monfils continued his comeback from injury to edge into the second round with a 6-4 2-6 7-5 victory over Kevin Anderson.
Both players broke serve four times in a close battle which lasted two hours and 25 minutes.
It was another welcome victory for the Frenchman who missed almost four months with a knee injury before returning last week at the Moselle Open where he reached the semi-finals.
World number 80 Ivo Karlovic won 76 per cent of his service points and hit nine aces past Marinko Matosevic of Australia in a 6-3 6-4 victory to set up a second-round meeting against third-seeded Canadian Milos Raonic.
Japan's Go Soeda will face fourth-seeded Frenchman Gilles Simon after defeating Thai wild card Danai Udomchoke 6-4 7-5 in his first-round match.
Seventh seed Jarkko Nieminen also made it through to the quarter-finals with a 7-6 (7/1) 6-2 victory over Philipp Petzchner.
The world number 38 enjoyed far more success with his first serve which proved to be the foundation of a win he earned in one hour 38 minutes.