For Karnataka, seamer Sreenath Aravind was the pick of the bowlers returning figures of 2/41.
After play was delayed for an hour and five minutes due to bad light, Umesh Yadav (4/73) got the wicket of overnight batsman and skipper R. Vinay Kumar (21) who was trapped in front trying to flick an innocuous delivery.
Soon after, Yadav -- making the most of the conditions -- brought an end to overnight centurion Nair's vigil (153 off 287; 20x4, 1x6) as the latter got a faint edge through to wicket-keeper Akshay Wadkar off a short delivery which he tried to cut.
Nair was batting on 148 on Day 2 with Vinay Kumar (20) for company. The pair, who had stitched together a 69-run stand for the ninth wicket partnership at stumps on Monday, saw their association coming to an end at 71.
Karnataka thus were all out for 301 taking a lead of 116 runs.
Vidarbha got off to a poor start with skipper Faiz Fazal (0) -- this season's second-highest run getter -- failing in the second essay as well.
Vinay Kumar, in only his second ball of the innings, got the batsman lbw with an incoming delivery from the middle stump which Fazal tried to guide down the on side.
Sanjay Ramaswamy (17) did not last long either, falling to a gem of a Stuart Binny (1/46) delivery which pitched on off stump and took a faint outside edge off the bat to wicketkeeper CM Gautam.
Alongwith experienced hat Wasim Jaffer (33), Ramaswamy was trying to build a partnership (36) for the second wicket but Jaffer also paid the price for playing across the line, getting lbw in the process off Aravind's bowling.
Satish and Wankhade then steadied the ship somewhat, helping the first-time semi-finalists take the lead by stitching together a 88-run stand for the fourth wicket. Although Wankhade fell one short of his half century, attempting a needless drive off Aravind with Vinay Kumar taking an easy catch at covers, Satish fought on.
Satish and Wadkar joined hands for a 45-run unbroken partnership for the fifth wicket with work still to be done and two days of play left -- meaning Karnataka still have the upper hand.
Brief scores: Vidarbha: 185 & 195/4 (Ganesh Satish 71 batting, Apporv Wankhade 49; Sreenath Aravind 2/41); Karnataka: 301 (Karun Nair 153, CM Gautam 73; Rajneesh Gurbani 5/94, Umesh Yadav 4/73)
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)