NEW DELHI, 21 Feb 2015 (AFP) - The Indian star began day three in blistering form, picking up two birdies on the first two holes and then cemented his lead with a steady round that featured only one bogey -- his first of the tournament. He now stands at 12 under overall.
Bangladesh's Rahman, who has been struggling with back problems recently, kept himself in contention with a round of 70, including a birdie on the 18th that gave him fresh hope of retaining his title.
Australia's Marcus Fraser was lying three strokes further back after a round of 67 while Sweden's Daniel Chopra was lying fourth equal on six under par for the tournament after firing a 65, the best round of the day.
Chowrasia, who already won three titles at the course in the heart of the Indian capital, had started the day just one shot clear of Rahman. But the 36-year-old said he had just concentrated on his own game.
"I played my own game and didn’t think that I'm playing in a match play with Siddikur," he said in comments on the Asian Tour website.
"If anyone is coming closer, let them. I just want to focus on my own game. I'm trying to be calm but I’m feeling very frustrated inside!"
The 30-year-old Rahman said the final hole of his round had given him an important boost for Sunday's finale.
"The birdie at the last was very important. Anything can happen in this game. I am looking forward to tomorrow and hopefully I can play the way I did on Thursday," added Rahman who carded a 65 on the first day.
The $1.5 million event is co-sanctioned by the Asian and European tours.
Leading scores after the third round of the Indian Open at Delhi Golf Club on Saturday (Indian unless stated):
201 - S.S.P Chowrasia 65-67-69
203 - Siddikur Rahman (BAN) 65-68-70
206 - Marcus Fraser (AUS) 69-70-67
207 - Prayad Marksaeng (THA) 68-70-69, Daniel Chopra (SWE) 70-72-65
208 - Anibarn Lahiri 73-65-70, Paul Peterson (USA) 69-68-71
209 - Adilson Da Silva (BRA) 71-70-68, Mithun Perera (SRI) 67-72-70, Richard McEvoy (ENG) 70-67-72, Joakim Lagergren (SWE) 65-71-73
210 - Ben Evans (ENG) 72-70-68, Jason Palmer (ENG) 70-71-69, Adrian Otaegui (ESP) 70-70-70, Peter Lawrie (IRL) 69-70-71
211 - Romain Wattel (FRA) 70-74-67, Pariya Junhasavasdikul (THA) 73-70-68, Kalem Richardson (AUS) 67-74-70, Jake Roos (RSA) 70-69-72, Chapchai Nirat (THA) 65-71-75