Aurobindo had no sat-guru. He did have a Vaishnava yogi as a upa-guru who gave him a most important technique. I paraphrase from memory from his Letters on Yoga.
*This will be easy for you since you are a poet and are used to watching thoughts form out of stillness. Sit and watch these thoughts but this time recognize that they are not you nor are they part of you. See them as happenings that are outside of you. Then reject them as something other than what you are. Throw them out when they come to intrude on your awareness. Then leave them outside, having nothing to do with you whatsoever. *I did as he said and in three days was free. I was enveloped in complete silence that expanded to encompass everything. >From that day on I was drowned in that silence. All mental and physical activity occurred outside of this vast stillness on the boundary of this world. Awakened to the Divine Mission The famous Alipore Bomb Case was the turning point in Sri Aurobindo’s life. For a year Aurobindo was an undertrial prisoner in solitary confinement in the Alipore Central Jail. It was in a dingy cell of the Alipore Jail that he dreamt the dream of his future life, the divine mission ordained for him by God. Aurobindo bore the rigours of the imprisonment, the bad food, the inadequate clothes, the lack of light and free air, the strain of boredom and the creeping solitariness of the gloomy cell. He utilized this period of incarceration for an intense study and practice of the teachings of the Bhagavad Gita. Chittaranjan Das defended Sri Aurobindo, who was acquitted after a memorable trial. His Practice of Yoga Sri Aurobindo began his Yoga in 1904. He had no helper or Guru in Yoga till he met Lele, a Maharashtrian Yogi in Baroda; and that was only for a short time. Meditating only for three days with Lele, Aurobindo followed the Yogi’s instructions for silencing the mind and freeing it from the constant pressure of thought. Sri Aurobindo himself once wrote in a letter about his practice of Yoga: "I began my Yoga in 1904 without a Guru. In 1908 I received important help from a Mahratti Yogi and discovered the foundations of my Sadhana". He started Yoga by himself, getting the rule from a friend, a disciple of Brahmananda of Ganga Mutt. It was confined at first to assiduous practice of Pranayama, for six or more hours a day. Aurobindo practised and meditated on the teachings of the Gita and the Upanishads.