Railways paceman Harvinder Singh took 3 for 45 to derail the fancied hosts who were reeling at 179 for six when stumps were drawn for the day.
Had it not been for the in-form Jadeja, who was batting on 74 with Sarandeep Singh (31 not out) for company, Delhi would have been in a far worse situation.
Delhi were off to a disastrous start after they won the toss and elected to bat on a pace-friendly track as they lost their first wicket on the third ball of the first over without even a run being added on the board.
There was no end to their miseries as they were soon reduced to 7-2. Akash Chopra (0) and Shikhar Dhawan (3) were joined by Rajat Bhatia (4) in the pavilion after the first six overs.
With Delhi tottering at 30 for five after Mithun Manhans was run out for 10 and Abhinav Bali was bowled by J S Rao for 8, Jadeja took control of the proceedings.
He raced to his 50 (4x4) in only 74 balls to show his class. His 74 came in 221 balls with the help of 9 boundaries.
Jadeja first put on 56 runs with Varun Kumar (30) but the later was caught off Harvinder in the 44th over. Sarandeep Singh then joined the action and managed to stem the rot alongwith his skipper.
J S Rao and Kulamani Parida picked one wicket each to complement the efforts of Harvinder Singh.