He polled 5,71,800 votes, pushing Congress' V Sunita Laxma Reddy (2,10,523) and BJP's T Jayaprakash Reddy (1,86,334) to second and third positions.
The seat was vacated by K Chandrasekhar Rao after he became Chief Minister. Rao had won with a margin of 3.97 lakh votes, the May elections.
TRS maintained its lead from the first round which widened as the counting progressed.