At close on the second day, the home team made 30 for one in eight overs in their second essay with Dinesh Karthik remaining unbeaten on 28 (31 balls, 5x4).
Still 80 runs in arrears, Tamil Nadu, which had managed a solitary point in the drawn encounter against Maharashtra, has a mountain to climb to prevent Mumbai from scoring an outright win.
Resuming at the overnight score of 20 for no loss, Mumbai lost Kukreja (30) and Rahane (four) in quick succession and were reduced to 55 for two. But Wasim Jaffer and Amol Muzumdar (43, 68 balls, 5x4) steadied the innings with a 61 run stand for the third wicket in 18 overs.
A minor collapse put the visitors were in a spot of bother at 155 for five. However, Nayar, with some exquisitely timed shots, resurrected the innings with a 72-run stand for the six wicket with Ajit Agarkar (22, 31 balls, 3x4, 1x6).
Tamil Nadu came back removing Agarkar and Ramesh Powar to restrict the visitors to 228 for seven, only to see Nayar adding another 74 for the eighth wicket in 14.3 overs with Vinayak Samant (39 not out, 72 balls 5x4) to see the team past the 300-mark.
For Tamil Nadu, left arm spinner Ramkumar claimed four wickets.
Brief Score (D-2):
Tamil Nadu Ist innings 206 and 30 for 1 (Karthik 28 n o; Powar 1 for 10) Vs Mumbai 317 all out (Abhishek Nayar 105, Jaffer 50, Muzumdar 43, Vinayak Samant 39; Ramkumar 4 for 88, Amarnath 2 for 66, R Ashwin 2 for 58)