Put in to bat, Punjab scored a competitive 174 for seven in their allotted 20 overs, but thanks to Sehwag, Gautam Gambhir (40 off 25) and Sumit Narwal (42 off 23), Delhi overcame the target with 10 balls to spare.
Sehwag and Gambhir, both of whom are out of the Indian contention, set the tone for a successful chase before Narwals onslaught got their team over the line.
Sehwag seems to have re-discovered his deadly form which deserted him in the Ranji Trophy and the subsequent one-dayers for the Vijay Hazare Trophy.
His innings had a 191 plus strike rate and comprised 13 fours. The 35-year-old had scored 42 and 22 and in the matches against Himachal Pradesh and Jammu & Kashmir.
He went into the tournament after scoring a match-winning hundred for Marylebone Cricket Club (MCC) against Durham in Abu Dhabi last month.
Gambhir, too, played his part well, hammering five fours and a six during a blazing knock.
Delhi comfortably reached 178 for four in 18.2 overs.
Earlier, contributions from Manan Vohra (41 off 22), Mandeep Singh (36 off 33) and Gurkeerat Singh (29 off 18) helped Punjab post a challenging total.
Punjab: 174 for seven in 20 overs (Manan Vohra 41, Mandeep Singh 36; Ishant Sharma 2/37, Parvinder Awana 2/41).
Delhi: 178 for four in 18.2 overs (Virender Sehwag 67, Sumit Narwal 42, Gautam Gambhir 40; Rahul Sharma 2/38).