In what is widely seen as a superb performance, Bharatiya Janata Party candidates were on the winning track in 28 of the 82 seats where officials gave early trends from vote count that began in the morning.
The PDP led by former chief minister Mufti Mohammed Saeed, who himself led in Anantnag, was a close second in 25 places.
The overwhelmingly Muslim Kashmir Valley has 46 constituencies while the Buddhist-dominated Ladakh accounts for four seats.
The ruling National Conference took the lead in 13 constituencies. Its estranged ally, the Congress, was ahead in 10 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 in the country's only Muslim-majority state.
A total of 48.29 lakh votes are to be counted Tuesday.
Most exit polls predicted a hung assembly in Jammu and Kashmir at the end of staggered polling.