The AAP's entry made Delhi polls a traingular contest.
That's the big question haunting the two principal parties who dominated the bipolar face-off in Delhi for two decades. Until today.
As the year-old rookie, the Aam Aadmi Party, springs the coup of Elections 2013 with exit polls indicating an impressive debut by the Arvind Kejriwal-led party, experts are now wondering how the Congress and the BJP failed in assessing the popular mood in Delhi.
Mr Kejriwal's party makes a strong debut with 17 seats - nearly a fourth of Delhi's 70 seats in the state Assembly - in a survey conducted by different agencies.
Throughout the campaign, both the BJP and the Congress dismissed Mr Kejriwal as an upstart with limited potential.
The BJP, hoping to topple the 15-year-old run of the Congress in the national capital, failed in reading the mind of the voters it so fervently wooed. The party's chief ministerial candidate, Dr Harsh Vardhan, said, "I think both the Congress and the newest party in this election are fighting for the second place."
The Congress was even less circumspect. When asked on Wednesday morning whether she sees Mr Kejriwal as a threat, incumbent Chief Minister Sheila Dikshit, though visibly disturbed, retorted, "One man who lives in Ghaziabad comes to Delhi and thinks he can sweep everything in sight. I mean is that even a party?"
The 76-year-old Congress leader, seeking a record fourth term, may have to eat her words on Sunday, when the votes polled in the four big states are counted.