At stumps, Sunny was unbeaten on 101 off 201 balls with the help of 11 boundaries and one six and giving him company was Jayant Yadav on 13.
However, Harayana did not have the best of starts after skipper Ajay Jadeja won the toss and decided to bat.
The visitors lost both their openers -- Nitin Saini (19) and Abhimanyu Khod (24) -- at the team score of 59 before Sunny resurrected Haryana's innings in Avi Barot's (64) company.
Barot found the fence nine times during his 141-ball patient knock before edging one to wicket-keeper Amol Ubarhande off off-spinner Akshay Wakhare's bowling in the 69th over of the day.
More From This Section
For Vidarbha, Shrikant Wagh (1/46), Amol Jungade (1/56), Sumit Ruikar (1/42) and Wakhare (1/54) scalped one wicket apiece.
Brief Scores:
Haryana 1st innings: 235 for four in 90 overs (101 not out, Avi Barot 64; Sumit Ruikar 1/42).