The Australian wildcard had overcome Mikhail Youzhny in his opening match, but fell well short of those standards in round two.
A former US Open champion, Hewitt spurned three break points which might have got him back into the contest, and Troicki was clinical when his chances arose to win the match in 61 minutes.
10th seed Mardy Fish had no such problems, blasting past Argentine Carlos Berlocq 6-3 6-1. The South American got off to a poor start, losing his focus when a Hawk-Eye challenge did not go his way, and allowing the home crowd hope to build up an early lead.
Fish cleaned up the first set, and was even less troubled in the second, winning through in 76 minutes.