The 24-year-old Bhullar, who has led the US$750,000 Asian Tour event from the opening day, retained his overnight two-shot lead at the Macau Golf and Country Club but rued two missed putts from close range over the last two holes.
Thai youngster Thitiphun Chuayprakong also shot a 69 to stay in contention for a maiden Asian Tour victory while Filipino Angelo Que (70), Scott Hend of Australia (69) and American Berry Henson (68) will enter the final round four shots back.
Three-time Asian Tour number one Thongchai Jaidee's challenge fizzled after a disappointing 73 while Bangladeshi Siddikur also failed to mount a run at Bhullar following a 72 which included five dropped shots in the middle of his round.
The supremely talented Bhullar will be aiming for a second victory within the space of a month but knows his challengers will not hand him victory on a silver platter. "I've won a few times wire-to-wire in India. The goal now is to do it on the bigger stage and on a bigger level," said Bhullar, who has a three-day total of 13-under-par 200.
"I've been in this situation a few times. I know it's a difficult thing. I'm going to try to do the same things as I did in India and keep it simple. Just repeat what I've been doing the past three days and play percentage golf."
The lead could have been bigger for Bhullar, ranked sixth on the Order of Merit, if he had not missed short putts in his last two holes. The Indian missed par from three feet on 17 and then failed to convert a birdie chance from a similar range at the last hole. In all, he snared five birdies against three bogeys as he maintained his chase for a fourth career victory on the Asian Tour.
"That's not the finish I was thinking of. I'm feeling positive and I'm feeling good. I've really improved my driving and it was long and straight today [Saturday]. I'm looking forward to playing well on Sunday," said Bhullar, who unknowingly drove the seventh green when the group ahead was still putting out.
Thitiphun, 20, continued to show his growing stature by staying in touch with Bhullar after signing for four birdies against two bogeys. He overcame his early nerves to remain as Bhullar's main threat.
"I played so-so but I scored. I felt pressure on the front nine. My swing wasn't good ... it changed. But I kept playing to my plan and that worked for me. Still 18 holes tomorrow [Sunday]. I will need to keep to my plan," said Thitiphun.
He featured in the final group at the Indonesian Masters last year alongside England's Lee Westwood and hopes to use the experience to good effect at the Macau Open, which is title sponsored for the first time by The Venetian Macao-Resort-Hotel.
"I hope to learn from my past experience. I'll just keep telling myself to relax. I'll need to breathe slowly in between shots," said the Thai. "Gaganjeet played well but I can still catch him. He's a superstar and playing really well at the moment."
After starting the week with a bad flu, Henson, last season's winner of the ICTSI Philippine Open, moved into contention with five birdies against two bogeys.
"Sometimes for me, I play good when I'm sick. I won in the Philippines when I was dehydrated. I think I'm over the hump and should feel better tomorrow [Sunday]. I'm hitting it really good but just missing a lot of putts. I counted the missed putts today [Saturday] and yesterday [Friday] and I could easily be 15 under. If my speed and lines are a bit better tomorrow [Sunday], hopefully they'll drop in," said Henson.
Filipino Que, chasing a fourth Asian Tour win, was kicking himself for not taking advantage of the easier front nine which he toured in 37 following a triple bogey on the fifth hole. But he fought back on the inward stretch with three birdies.
"I've been starting bad the last three days. First round I was two over after five, yesterday [Friday] I was two over after seven and today [Saturday] I was three over after six. I was hitting it good, just one bad hole. Luckily I held myself together and came back pretty good," said Que.
"On this course, if you start making putts on the front nine, you can go seven or eight under which is possible. But I'm just enjoying where I am right now. I'll just play my own game and won't even look so much at the leaderboard.
"Gaganjeet is in form. He has been playing well the past few months, top-10s and winning once. He's a pretty hard man to beat."