Ramsay, who has held on to the lead since day one, posted a one-under-par 70 for 11-under-par 202 to hold a narrow one-shot lead over Asian Tour Qualifying School graduate Jaakko Makitalo of Finland.
Makitalo, playing one flight in front of Ramsay, charged into contention for a first Asian Tour win as he returned with a 68 at the approximately US$1.25 million event.
Thailand's Thaworn Wiratchant (67), winner of the 2005 Hero Indian Open and 19-year-old Panuphol Pittayarat (69) were a further shot back with James Morrison (67) of England at the Karnataka Golf Association course.
Ramsay, who is playing on a sponsor's invitation, knows it will be a close race to the finishing line as six players are within three shots off the lead.
"I actually played nice. I found it tough to play with the wind blowing all over the place. I needed to make some putts which I didn't. It was a case of being close but not close enough today," said Ramsay, a two-time winner in Europe.
"It is surprising to be leading in a tournament with the way I putted. If I can putt better, then I think there's a better score out there," he added.
Makitalo eagled the par five 11th hole for the second successive day after hitting his hybrid to four feet from the hole. He could have shared the lead if not for a bogey on the last.
"It is always nice to have people and the television crew following me. You don't get mad and do stupid things. The only way I can ruin my game is if I lose focus, get mad and do stupid errors," said the 31-year-old, who started playing baseball before switching to golf.
"There's definitely going to be nerves. I was nervous today but I'm going to play like how I've been playing and avoid looking at scoreboards," said Makitalo, whose best result on the Asian Tour was a tied 22nd at the 2012 Worldwide Holdings Selangor Masters in Malaysia.
Panuphol's patience was rewarded with four birdies against two bogeys and admits that his performance this week has surpassed his expectations.
"I didn't feel angry at all today. I was calm out there. I played with Chapchai (Nirat) and we kept talking and that kind of eased the pressure. I'm not feeling any nerves. I'm further than I thought. My goal was to finish top-20 this week but I'm close to winning now. I don't feel any stress or nerves," said Panuphol, who is in the hunt for a first Asian Tour win.
Thaworn, who holds the record of 14 Asian Tour titles, posted a flawless round highlighted by four birdies and is aiming to win the Hero Indian Open for the second time in his career.
"I want to win again but I can't control what the others shoot. I've been hitting it quite good and making the putts. It was a solid round out there. I've been consistent this year and it is the same this week," said the 45-year-old, who has won twice on the Asian Tour this year.
Shiv Kapur led the local charge with a round of 68 as he lies in ninth position on 206 but it was local boy Anirban Lahiri who made the biggest move on the leaderboard with a 66 highlighted by two chip-ins on holes seven (25 feet) and nine (15 feet).
"Every par I made at the back felt like a birdie because I felt like I could make anything. I think I'm still in a great spot because I have nothing to lose. I can just go out there tomorrow and shoot my lights out. I got everything to play for," said Lahiri, a two-time Asian Tour champion.
Scores after round 3 of the Hero Indian Open 2012 being played at the par 71, 7068 Yards Karnataka Golf Association Golf Club course (a- denotes amateur):
202 - Richie RAMSAY (SCO) 66-66-70.
203 - Jaakko MAKITALO (FIN) 67-68-68.
204 - James MORRISON (ENG) 66-71-67, Thaworn WIRATCHANT (THA) 69-68-67, Panuphol PITTAYARAT (THA) 67-68-69.
205 - Arnond VONGVANIJ (THA) 71-67-67, Angelo QUE (PHI) 68-68-69, Chapchai NIRAT (THA) 67-68-70.
206 - Shiv KAPUR (IND) 67-71-68.
207 - Anirban LAHIRI (IND) 70-71-66, Chiragh KUMAR (IND) 69-71-67, Jyoti RANDHAWA (IND) 72-68-67, Scott HEND (AUS) 71-69-67, S. CHIKKARANGAPPA (am, IND) 72-68-67, Gaganjeet BHULLAR (IND) 68-69-70.
208 - Jonathan MOORE (USA) 69-72-67, Kalle SAMOOJA (FIN) 67-72-69.
209 - Peter HANSON (SWE) 70-71-68.
210 - Chinnarat PHADUNGSIL (THA) 75-65-70, Jason KNUTZON (USA) 68-70-72, Scott BARR (AUS) 70-68-72, Adilson DA SILVA (BRA) 70-68-72.