Mangaonkar overcame the national junior champion 7-11, 7-11, 11-3, 11-1, 11-6 in a quality championship round that lasted 70 entertaining minutes.
The trio of Megha Bhatia of Haryana, Ashita Bhengra of Tamil Nadu and Akanksha Salunkhe of Goa was the toast of the day after the girls fashioned stunning victories.
Sub junior national champion and Asia No 5 Megha Bhatia kicked off a day of exciting action when she rallied from 0-2 to snatch a pulsating 7-11, 9-11, 11-4, 16-14, 11-6 win over top seed Navmi Sharma of Maharashtra for her maiden CCI-Western India under-13 title.
Bhatia ignored the early setback and initiated a spectacular recovery with steely determination to force the decider, after snatching the crucial fourth set over extra points.
National semi-finalist and top seed Ashita Bhengra lived up to her reputation but not before facing a strong challenge from second seed Koel Shankar of Maharashtra to win the under-15 crown 11-5, 12-10, 14-12 in a tight finish.
Akanksha Salunkhe completed the action-packed day when she shocked top seed Aishwarya Bhattacharya of Maharashtra 15-13, 11-6, 13-11 in another thriller for the under-17 title. Veer Chotrani of Maharashtra, Yash Bhargav of Delhi and Ranjit Singh of UP were the other significant winners.