Himachal limited Haryana to 122 for nine before reaching the target with four balls to spare.
Number nine and 10, Rahul Singh and Akshay Chauhan, scored an unbeaten 13 and 15, to take Himachal home after they were struggling at 65/6 in the 14th over.
Robin Bist was the top scorer for Himachal with 27.
Brief scores: Haryana 122/9 in 20 overs (RM Dagar 39, HV Patel 26; B Sharma 3/20)
Himachal Pradesh 123/8 in 19.2 overs (Robint Bist 27; A H Hooda 3/15).