Monga, third last week at the 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 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.
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.
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But at 149 she is three behind Gauri and she could still give the leader a run for her money in the closing stages of the tournament.
Astha Madan (72-76) also lost her top place in Category A, as Tvesa Malik (74-73) moved to first. Gurbani Singh (75-74) was lying third.
In Category C, Sifat Sagoo stayed (83-86) was still leading with Ananya Barthakur (89-84) second. Oviya Reddi (91-85) was third.