The Pro-Tem Speaker Kalidas N. Kolambkar administered the oath to all the MLAs starting at 8 am and completing shortly after noon, with five members reportedly absent.
The day started early for most the MLAs with many reaching Vidhan Bhawan well in advance, newcomers alighting with excitement and anticipation, around 7 a.m.
There were some first-timers like Sena's Aaditya Thackeray who first went and prayed at the Siddhi Vinayak Temple before rushing to the oath ceremony at Nariman Point.
At the Vidhan Bhavan entrance, many were surprised to see Nationalist Congress Party MP Supriya Sule, Aaditya Thackeray and several Congress bigwigs warmly welcoming them, almost like in a wedding reception.
They received MLAs of all parties with equal ease, 'namaste' with folded hands and wishing them the best of luck, and many, especially from the BJP were visibly taken aback.
When cousin and former Deputy CM Ajit Pawar arrived, he smiled at Supriya, greeted her warmly, shook hands and then hugged her, who reciprocated in equal measure and even bent down to touch his feet.
Moments later, even former Chief Minister Devendra Fadnavis arrived to Supriya's warm welcome with a handshake and a gentle touch on the shoulder.
Her other big hugs were reserved for a few selected MLAs, including her own nephew Rohit Pawar, the young Sena cub Aaditya Thackeray, Anil Deshmukh and some more.
She greeted with respect and courtesy to many senior leaders like BJP's former Speaker Haribhau Bagade, former minister Ashish Shelar, NCP state chief Jayant Patil, Congress state chief Balasaheb Thorat, Sena's Legislative Party Leader Eknath Shinde and other bigwigs.
The mood was completely relaxed after the month-long political turmoil that rocked the state and culminated in the Sena-NCP-Congress and their allies unanimously electing Uddhav Thackeray as the next Chief Minister of Maharashtra.
Thackeray will be administered the oath of office and secrecy by the Governor B. S. Koshyari at a mega public function scheduled at Shivaji Park on Thursday evening.
A Sena source said that a galaxy of leaders from the state and Centre besides top leaders from other states, celebrities, industrialists and diplomats are likely to attend the grand event.
( With inputs from IANS )