All India Congress Committee office at Akbar road in Delhi (Press Trust of India photo)
As the Congress was reduced to zero seats in Delhi, Ajay Maken, who led the party's disastrous campaign, resigned as its general secretary.
"I believe I should take responsibility and therefore resign. I was face of the Congress campaign and haven't been able to win the seat which I contested in as well," Mr Maken told reporters, owning responsibility for his party's decimation in Delhi, which has ruled for 15 straight years.
"This result has nothing to do with party leadership," he added.
Mr Maken and all other 69 candidates of the Congress were defeated in the election.
Congress president Sonia Gandhi and vice president Rahul Gandhi both congratulated Arvind Kejriwal for his Aam Aadmi Party's landslide win.
In 2013, the Congress won eight of 70 seats, placing a distant third after the BJP and AAP. It was a massive jolt to the party as well as its chief campaigner Sheila Dikshit, a three-time chief minister.
This time, the Congress has performed far worse than was widely expected. Surveys had predicted that it would stay in single digits but no one had gone below two seats.
The scale of defeat is especially humiliating for Mr Maken, who does not share the best of ties with Sheila Dikshit.
For the Congress, yet another defeat meant a reenactment of familiar scenes outside the Congress headquarters - a group of workers clamouring for Sonia Gandhi's daughter Priyanka Gandhi Vadra and shouting slogans of "Priyanka
lao, Congress
bachao!"
Insulating Rahul Gandhi from any blame, Mr Maken said the Delhi election was fought on local issues.
Some party leaders called for deep introspection and a relook into the party's ideological construct.
Former Jammu and Kashmir chief minister Omar Abdullah tweeted, "If there is lesson for the #Congress in this it is that Modi & BJP aren't unbeatable if you take the fight to them, don't wait for mistakes."