Left-backed Congress candidate Bayron Biswas is leading from the seat by over 20,000 votes after 12 rounds of vote counting.
Buoyant by the trend, Chowdhury said, "This result shows Mamata Banerjee is not invincible. Congress can win and rout (Trinamool Congress)."
"Congress may lose elections but won't fade away," the firebrand Congress MP added.
The Congress candidate is followed by Trinamool candidate Debashish Banerjee.
The seat was won by the Trinamool in the 2021 assembly elections.
If Biswas emerges as winner, the Congress will open its account in the assembly which only has Bharatiya Janata Party (BJP) and ISF as opposition parties.