In what is being seen as a stunning show, BJP candidates had surged ahead in 23 of the 87 constituencies where counting trends were available. The PDP was ahead of others in 21 places.
The ruling National Conference fared badly, its candidates taking the lead in just 21 of the 87 constituencies. Its estranged ally, the Congress, was set for a rout. It was ahead in only 14 seats.
Minister of State in the Prime Minister's Office Jitendra Singh said: "This will be a turning point for BJP and for Jammu and Kashmir politics."
The BJP led by Prime Minister Narendra Modi had campaigned vigorously in Jammu and Kashmir with a pledge to win 44 seats -- and assume power on its own for the first time.
A total of 48.29 lakh votes are to be counted.
Most exit polls have predicted a hung assembly in Jammu and Kashmir, the country's only Muslim-majority state.
Among those on the winning track were PDP leader and former chief minister Saeed (Anantnag), Chief Minister Omar Abdullah (Sonawar) and Deputy Chief Minister Tara Chand (Chhamb).
Also Read: BJP ahead of everyone in Jharkhand
PDP races ahead in Kashmir, BJP follows