The BSP, which fought the polls without any allies, bagged 202 seats in the 403-member assembly.

Samajwadi Party suffered severe losses, winning 90 seats Chief Minister Mulayam Singh Yadav, who won from both Gunnaur and Bharthana constituencies, conceded defeat in the wake of his party's drubbing and resigned in the afternoon.

The BJP, which had hoped to continue its upswing in assembly polls in Punjab and Uttarakhand states and Mumbai Corporation, lost a lot of ground. It won 50 seats.

Congress, helped by its star campaigner Rahul Gandhi, got 22 seats, three less than last time.

The key to BSP's success, political analysts said, was 51-year-old Mayawati's wooing Brahmins and other upper caste voters in a big way in a rainbow coalition helped add to its traditional vote base of backward castes and Muslims.

Celebrations broke out at Mayawati's residence in Lucknow, capital of Uttar Pradesh, where they distributed sweets among themselves and to hordes of journalists. There were celebrations elsewhere in the state too as party workers set off fireworks.

Congress indicated it was open to backing Mayawati in forming a government.

In the 2002 assembly elections, the BSP had won 99 seats while Samajwadi Party bagged 143. The BJP was third last time too, winning 88 seats and Congress had secured 25 seats.

The victory was a personal triumph for Mayawati, daughter of a lowly government employee, as this was the first major election she led her party in the absence of her

political mentor Kanshi Ram who had founded BSP and died last year.

Mayawati's first sting as Uttar Pradesh Chief Minister came in 1995 when her party came to power in alliance with Samajwadi Party. However, it lasted for just for four months as the coalition with Mulayam Singh Yadav ended abruptly.

In 1997, the spinster again became Chief Minister for sixmonths under an agreement with BJP. The arrangement did not work and ended in political chaos in the state in late 1997.

Mayawati occupied the Chief Minister's office for thethird time in 2002 and this time her government was formed with the support of BJP. This lasted for 18 months and she had to resign in 2003 after her indictment by the Supreme Court in a corruption case. A CBI probe was also ordered in the case.