Monga, third last week at the Usha Karnataka Ladies event, is one shot clear of Gursimar Badwal (74-73), who shares the second place with Tvesa Malik (74-73).
With the course at the KGA still not yielding easy scores, there were no sub-par scores for the second day in a row.
Noida-based Monga, who had one of brightest moments of her career in the 2011 Usha Queen Sirikit Cup in Delhi when she was tied for third place, dropped two bogeys on the front nine, but then made up with steady streak of eight pars followed by a birdie on 18th on back nine.
Overnight leader Astha Madan dropped down the leaderboard with a second round 76 after a first round 72. That put her at 148 in tied fourth place alongside Raksha Phadke (74-74).
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Gurbani Singh, the No. 1 last season and winner of both events this season, continued to trail in sixth place as she carded 74 after a first round 75. But at 149 she is three behind Monga and she could still give the leader a run for her money in the closing stages of the tournament.
In Category B, Amrita Anand (73-77) opened a big seven-shot lead over Gurjot Badwal (85-78) and Suchitra Ramesh (81-87) was third.
In Category C, Sifat Sagoo (83-86) was still leading with Ananya Barthakur (89-84) in second position. Oviya Reddi (91-85) was third.