Opener Shikhar Dhawan cracked 82 and Akash Chopra remained unbeaten on 81 as the visitors ended the day with an upperhand over the hosts who folded up in their first innings after resuming on 231 for six.
Skipper Virender Sehwag, looking for a big score after a string of poor runs, was batting on 40, laced with five boundaries, when stumps were drawn for the day.
Earlier, Mayank Tehlan departed without scoring having been bowled by Anil Kumble.
Delhi got a sound start with Dhawan, who hit eleven fours in his 148-ball knock, and Chopra, who has so far hit eight fours facing 210 balls, putting on 142 runs for the opening wicket.
Sehwag struggled initially, surviving three appeals -- two lbw and one caught behind -- by Kumble but then regained his touch to steady the boat.
Brief scores: Karnataka 283 all out in 106.5 overs (Barrington Rowland 81, B Akhil 62, Robin Uthappa 31; Chetanya Nanda 3/43, Sehwag 2/39, Kunal Lall 2/50) vs Delhi 213 for two in 75 overs (Dhawan 82, Chopra batting 81, Sehwag batting 40; Sunil Joshi 1/49, Kumble 1/73).