On a day the CPM was swept away by the Mamata wave, the Marxists clung on to a win in Jadavpur, where Sujan Chakraborty trounced the man who had beaten Buddhadeb Bhattacharjee in the 2011 polls.

Chakraborty defeated power minister and former chief secretary Manish Gupta by 14,942 votes. In the 2011 Assembly elections, Gupta had defeated Bhattacharjee, his former boss, by 16,684 votes.

Chakraborty, at 57, can be called a young face amidst the party's geriatric leadership. He was not part of the Left Front governments led by Jyoti Basu or Buddhadeb Bhattacharjee. That may have contributed to Chakraborty's win.

Another factor that is believed to have tipped the scales in Chakraborty's favour was the door-to-door campaign that was launched three months before the elections.

"We had started the door-to-door campaign well in advance and were able to convince people about the negative aspects of the Trinamul government. We have been able to convince voters about the Mamata Banerjee government's failure to create jobs and improve the law-and-order situation," said Ramen Chakraborty, a CPM member for 26 years and resident of Gangulybagan.

Trinamul leaders feel Gupta lost the polls because he was not as visible in the constituency as his CPM rival was, before the polls. Party sources said the top leadership had feared that Gupta would lose.

A Mamata confidant had "called" the Jadavpur results after poll day, telling fellow party leaders that Gupta had "lost".

On Thursday, both Chakraborty and Gupta reached Gitanjali Stadium, where the votes of the Jadavpur and Kasba constituencies were being counted, around 8am.

Chakraborty took a lead soon after the counting started and held on till the end. By 11am, after eight rounds of counting, he was ahead by over 8,000 votes. Gupta left the counting centre.

It later emerged that Chakraborty had won all 10 wards of the Calcutta Municipal Corporation in his constituency - 96, 99, 101, 102, 103, 104, 105, 106, 109 and 110.

While waiting for his winner's certificate, Chakraborty was seen engaged in a dissection of the Jadavpur verdict vis-a-vis the overall result with his poll agents.

"People in Jadavpur are very much aware of the prevailing situation. They understood that another Trinamul government was not ideal for the state," the victor said.