Having conceded a 66-run first innings lead, Karnataka scored a comprehensive 475 for nine declared with as many as six batsmen getting to half centuries.
At stumps, Delhi were in trouble at 40 for three chasing a huge target of 410 with R Vinay Kumar and HS Sharath sharing the spoils.
Getting 370 runs on the final day of a seaming Chinnaswamy track is certainly out of question but it will be a challenge for the visiting batsmen to avert a defeat which would virtually end their chances of qualifying for the knock-out stage.
Everything now depends on senior pro Mithun Manhas who has already scored 529 runs this season. Manhas and Rajat Bhatia are the two players on whom it depends whether Delhi can hold on to their three points from the encounter.
The Karnataka batsmen did extremely well with their opening pair of Robin Uthappa and Lokesh Rahul scoring 81 and 73 respectively adding 140 runs in the process.
Manish Pandey (61) and Stuart Binny (85, 9x4, 4x6) added 145 runs for the fifth wicket to further consolidate the lead.
The 83-run stand for the eighth wicket between CM Gautham and Abhimanyu Mithun took the lead beyond 400. Gautham scored 71 while Mithun smashed 52 off only 40 balls. Parvinder Awana git three wickets and finished with a match-haul of eight wickets.
Brief Scores: Karnataka 192 & 475/9 decl (Stuart Binny 85, Robin Uthappa 81, Lokesh Rahul 73, CM Gautham 71, Manish Pandey 61, Abhimanyu Mithun 52, Parvinder Awana 3/89).
Delhi 258 & 40/3 (Shikhar Dhawan 18, HS Sharath 2/9, R Vinay Kumar 1/14).
