The most potent Durga Prayer for Navaratri "BHAVANYASHTAKAM (Eight stanzas of Bhavani Prayer)" written by Adi Shankaracharya in Sanskrit translated in English:
Navratri 6th day , 6th Stanza
प्रजेशं रमेशं महेशं सुरेशं, दिनेशं निशीथेश्वरं वा कदाचित्।
न जानामि चाSन्यत् सदाSहं शरण्ये, गतिस्त्वं गतिस्त्वं त्वमेका भवानि।
meaning
Oh Goddess Supreme !
Brahman, Vishnu, Maheshwara, Indra, Chandra or Surya I do not know.
O Mother of the universe, you are known for your compassion.
You are my only savior, my eternal refuge.
