Karnataka now have 14 points in their group.
The match could not evoke interest after Vidarbha's first innings folded at 447 runs, giving Karnataka a 172-run first innings lead.
With only academic interest left in the match, Karnataka made 81 for three, losing Robin Uthappa (18), Lokesh Rahul (6) and Kunal Kapoor (7).
The umpires called of the match when Manish Pandey and Ganesh Satish were unbeaten on 28 and 14 respectively.
Pacer Abhimanyu Mithun (4/60) picked up three more wickets today while left-arm spinner K P Apanna scalped three wickets to leave Vidarbha 172 runs short of the hosts' total.
Mithun, who had removed Faiz Fazal yesterday, gave a rollicking start to Karnataka by dealing two quick blows.
He first sent packing Shalabh Srivastava for 97 which broke a fighting 228 runs partnership for the third wicket and then had centurion Amol Ubarhande for 137 nine runs later.
After the fall of Ubarhande and Srivastava, Vidarbha never seemed to come back in the game as they lost in form Hemang Badani (11) and Apoorv Wankhade (19).
Resuming at 395 for six at lunch, Vidarbha quickly lost their last four wickets after adding 52 runs with Appanna trapping Gaurav Upadhyaya and Sandeep Singh.
