Somdev's first round appearance at the Cincinnati Masters following a successful qualifying campaign earned him 35 points and helped his cause.
Somdev rose to his career best 96 early this month but his stay in top-100 was short-lived as he got out of the elite bracket following a poor show at the Washington ATP event.
A semi-final appearance at the ATP Challenger event in Uzbekistan helped Vishnu Vardhan take a huge jump of 58 places to 335, the second best ranking in the singles for India after Somdev.
In the doubles ranking, Mahesh Bhupathi gained a place to seventh after ending runners-up at the Cincinnati Masters along with Max Mirnyi.
Leander Paes (6) and Rohan Bopanna (33) were static.