The two went head-to-head on the hard court in China as Murray, who was billed as the tournament headliner, claimed a 6-3 6-3 triumph.
Murray is battling to secure a late place at the ATP World Tour Finals in November, with the two-time grand slam winner sitting 11th in the rankings.
However, with the seventh-ranked David Ferrer knocked out of the Shenzhen tournament by Viktor Troicki on Thursday, Murray's chances received a boost.
And the Scot was in buoyant mood after defeating the 141st-ranked Indian, highlighting the humidity as a major obstacle.
"I thought I did pretty well," he said. "[Devvarman] makes very few mistakes. He's a very solid player and he moves well.
"It was very humid out there. It was good to have a tough workout like that."
Murray will face Lukas Lacko in the quarter-finals on Friday, with a semi-final against either Juan Monaco or Richard Gasquet on the cards should he see off the Slovakian.