Shiv Sena chief Uddhav Thackeray on Thursday sworn-in as the new Maharashtra chief minister in a glittering ceremony at Mumbai's Shivaji Park. The oath to Thackeray was administered by Governor Bhagat Singh Koshyari. Thackeray, 59, became the third Sena leader after Manohar Joshi and Narayan Rane and first from his family to occupy the top post.