The 27-year-old spinner returned career-best figures on a slow turner to contain the visitors to a meagre 179.
Earlier, Bengal, resuming at overnight score of 275/6, were all out for 315, 67 minutes into the day's play at the Jadavpur University campus ground, Salt Lake.
Bengal were zero without loss in their second innings at close on a bowlers day, that saw 14 wickets tumble.
Lodhgar, playing only his second Ranji match, having made his debut versus Tripura in 1998-99, exploited whatever bounce existed on the wicket to rip through the Karnataka middle order and tail in a single spell after being introduced into the attack a little before tea.
For the tourists, Sujith Somasundar, returning to the team after a gap of three years, top scored with 48 (140 m, 97 b, 9x4) but Karnataka lost wickets at regular intervals as their innings folded in a little over five hours. The last seven wickets fell by adding only 64 runs.
In the morning, Sourav Ganguly, who played the tie to get vital match practice ahead of India-Pakistan one-dayer after having missed two Tests due to a groin injury, disappointed his fans with a brief stay in the middle (27; 76 b, 2X4).
Karnataka first innings: 179 (S Somasundar 48; M Lodhgar 6/28).
Bengal 1st innings: (overnight 275/6)
A Das lbw b S Joshi 111
D Dasgupta lbw b D Ganesh 98
D Gandhi b D Ganesh 16
R Gavaskar lbw b R Vinaykumar 6
S Ganguly c S Somasunder b R Vinaykumar 27
L R Shukla c S Binny b D Ganesh 0
S Sanyal run out 6
S Lahiri not out 39
M Lodhgar c T Naidu b R Vinaykumar 0
R Bose c S Somasunder b S Joshi 0
S S Paul b D Ganesh 0
Extras: (b-4,lb-1, nb-5, w-2) 12
Total:(all out in 106 overs) 315
Fall of wickets: 1-199, 2-226, 3-235, 4-235, 5-236, 6-244, 7-301, 8-301, 9-310
Bowling: D Ganesh 29-7-80-4, Vinay Kumar 29-11-64-3, S Binny 9-3-26-0, S Joshi 23-7-70-2, U Patel 12-0-54-0, S Somasundar 3-1-12-0, R Barrington 1-0-4-0.
Karnataka first innings:
J Arun Kumar c D Dasgupta b S Sanyal 25
B Rowland c D Dasgupta b R Bose 0
S Somasundar c M Lodhgar b S Lahiri 48
S Ponnappa lbw b R Bose 26
V Bhardwaj not out 25
T Naidu c (sub) A Majumdar b M Lodhgar 11
S Binny c (sub) A Majumdar b M Lodhgar 0
S Joshi c R Gavaskar b M Lodhgar 10
D Ganesh c A Das b M Lodhgar 14
R Vinay Kumar c S Ganguly b M Lodhgar 1
U Patel c D Dasgupta b M Lodhgar 0
Extras: (b-2, lb-2, nb-15) 19
Total: (all out in 67.1 overs) 179
Fall of wickets: 1/1, 2/60, 3/92, 4/115, 5/128, 6/130, 7/147, 8/169, 9/173.
Bowling: S S Paul 17-3-50-0, R Bose 15-3-40-2, S Sanyal 9-2-30-1, S Lahiri 11-3-27-1, M Lodhgar 15.1-4-28-6.
Bengal second innings:
A Das batting 0
D Dasgupta batting 0
Total:(for no loss in 0.1 overs) 0
Bowling: S Joshi 0.1-0-0-0.