The 17-year-old, who co-led the field after the first round in 2012 and finished eighth, was also 13th last year. Today she was one-under at the turn and then one-over when she came to the 18th.
"I tried to go over the water and messed up and lost the ball. I three-putted from 70 feet for a costly double," said a smiling Aditi.
Smriti Mehra one of the three players yet to finish was four-over with three holes to go. She will come back to finish her round in the morning.
Among other Indians, Amandeep Drall (77) was tied 37th, Sharmila Nicollet with her 78 was tied 47th, as was Gursimar Badwal. Tanya Wadhwa, Vani Kapoor and Saaniya Sharma shot 79 each.
More From This Section
At the top, rookie Emily Kristine Pedersen from Denmark, playing in the second last group, beat fading light to birdie her final hole on the ninth and take lead.
At two-under 70 she held a one shot lead as only three players carded under par rounds.
Sergas, whose Indian connection includes a love for Indian cooking and early coaching by Donata di Ponziano, who has visited India often in the past two decades, carded 71 and shared the second place with Thai Saraporn Chamchoi, who was taught golf early in her career by Thai legend Thongchai Jaidee. Saraporn was third at the 2013 Hero Indian Open.