Thanjavur Bishop Devadoss Ambrose hoisted the flag, an event witnessed by a large number of pilgrims this evening.
The festival would conclude on September 8, the birthday of the 'Our Lady of Good Health'.
On all the festival days, special prayers would be held in all South Indian languages and while the idol of 'Our Lady of Good Health' taken around in procession in the evenings.
Lakhs of devotees, including those who undertake 'padayatra', from across the country and overseas throng the shrine during the festival to thank the 'Lady' for making their dreams come true.
District administration has made elaborate arrangements, including tight security and medical facilities, for the festival.
Special buses are being operated from various parts of the state while Railways is operating trains from Mumbai, Vasco-Da-Gama and other places.