Mumbai, March 10 (IANS): Karun Nair's unbeaten 310 helped Karnataka reach 618/7 on the third day of the Ranji Trophy final at the Wankhede Stadium here on Tuesday.

With only two days remaining, Karnataka have taken a mammoth 484-run lead that puts them on course for retaining the title.

Chasing Tamil Nadu’s first innings total of 134, the defending champions were 323/5 on Monday. Both the overnight batsmen Karun Nair, then on 130, and Lokesh Rahul, then on 131, continued to flay the opposition bowlers.

Indian Test opener Rahul was dismissed at the personal score of 188 when he offered a catch to Vijay Shankar off Malolan Rangarajan. The right-hander hit 17 fours and three sixes during his ninth first-class century.

But the 22-year-old had already put his team in position of strength at 470/6. He and Nair forged a 384-run stand for the sixth wicket that marked a complete turnaround. They had joined hands when Karnataka were reeling at 84/5.

Nair, 23, notched up his first triple hundred in the first-class cricket and ensured that his team bats Tamil Nadu out of the contest.

He has so far faced 533 deliveries, hitting 45 of them to the fence and one over it. After the wicket of Rahul, Shreyas Gopal (11) also lost his wicket but that didn't bother right-hander Nair. R. Vinay Kumar provided a very good support from the other end and the skipper is on 41.

It will be a formality when Vinay declares the innings on Wednesday. Considering the huge lead, Karnataka are expected to go for the jugular. Even if Tamil Nadu put up a brave fight in the second innings, Karnataka will be runaway winners on the basis of first innings lead.

Brief scores: Tamil Nadu 134 all out vs Karnataka 618/7 (Karun Nair 310 not out, Lokesh Rahul 188; Lakshmipathy Balaji 3/95, Malolan Rangarajan 2/155) at stumps on Day 3.