At stumps on day two, Haryana were 105 for six with captain Joginder Sharma (6) and Mahesh Rawat (16) in the middle, with the writing clear on the wall.
Earlier resuming on 330 for seven, Delhi were all out in their first innings for 382.
In reply, it was the hosts' horror story as Delhi's comeback man Amit Bhandari's (3/18) early two-wicket burst pushed Haryana to the back foot and then leggie Chetanya Nanda (3/36) ran through the middle order.
Sehwag too chipped in, castling Joginder Sharma (12) and Tejinder Mann (1) and also dropping curtain's on the hosts' innings at 113 by effecting Sanjay Budhwar's run out.
Asked to follow on, Haryana had a mountain to climb and they soon found themselves in the hole.
After the opening pairs had put on 32 runs, Haryana landed in morass again and the next 10 runs cost them as many as four wickets.
Nanda drew first blood when Nitin Saini (13) edged the leggie to Aakash Chopra and Sumit Sharma (16) joined him in the pavilion two runs later with Chopra again taking the catch, this time off Sehwag.
Nanda struck another blow by trapping Ankit Rawat (2) and then cousins conspired as Sehwag removed Sanjay Bamel who was caught by Mayank Tehlan. Haryana was gasping for breath at 42 for four at that stage.
Just when Sachin Rana (20) and Sandeep Singh (20) had begun to show signs of some resistance, Haryana suffered a double trouble with Nanda clean bowling Rana and then removing Sandeep Singh to leave Haryana reeling at 86 for six. Nanda's second innings figure read 9-0-51-4.
While Ashish Nehra is a pale shadow of himself, the spin duo of Nanda-Sehwag looked more threatening in the second innings and Delhi captain Sehwag would like to complete the formalities early tomorrow when play resumes.
Delhi 382 ( Sehwag 106, Akash Chopra 84, Rajat Bhatia 90; Amit Mishra 4 for 80, Tejinder Mann 2 for 85, Sanjay Budhwar 1 for 68) Vs Haryana 113 (Sachin Rana 54; Bhandari 3 for 18, C Nanda 3 for 36 Sehwag 2 for 6) and 105 for 6 (Sachin Rana 20 Sandeep Singh 20; C Nanda 4 for 37, Sehwag 2 for 37)