In a statement, Thackeray said Banerjee led the fight for Bengal's self respect single-handedly, adding that "all credit goes to the Bengal tigress for the win".
Thackeray, who heads the Shiv Sena, said the prime minister, Union home minister, ministers from the Centre and several states descended on WB to defeat Banerjee.
"But she defeated all these forces. I congratulate her and the courageous people of Bengal," he said.
In a sarcastic vein, the Maharashtra chief minister added that if everybody, an apparent reference to the Narendra Modi government at the Centre, was done with politics, then "let us unite to focus on the battle against the COVID pandemic".