Nair's 45-ball 64, laced with nine hits to the fence, helped Delhi recover from a precarious position after the visitors had reduced the home side to 9/2 after three overs.
Electing to bat after calling the toss correctly, Daredevils were off to a disastrous start, losing the key wickets of opener Sanju Samson (2) and one down Shreyas Iyer (3) cheaply.
Nair and wicketkeeper-batsman Rishabh Pant (36) then steadied the ship with a 74-run third wicket stand as the right-left combo took the attack to the opposition in no time.
The first three overs yielded only 11 runs for Delhi before Nair started the onslaught slamming Washington Sundar and Ben Stokes for five boundaries in two overs.
Pant wasn't left too far behind, slapping Sundar for a flat six over midwicket before milking Shardul Thaur for three boundaries as Delhi got back the momentum to yield 62 runs in the next five overs.
The strategic time-out once again brought smiles back to the Pune camp, but not before Pant had smacked leg-spinner Adam Zampa for a four and six.
Zampa, however, got the southpaw the very next ball with a flatter delivery which Pant after facing 22 balls and hitting four boundaries and two sixes, failed to connect properly to be caught by Daniel Christian at long-on.
The fall of Pant brought in West Indian Marlon Samuels (27 off 21), who looked good during his 21-ball stay at the crease.
Samuels slammed two consecutive maximums of pacer Shardul Thakur to add 34 runs for the fifth wicket with Nair before stumper Mahendra Singh Dhoni plucked off a stunning catch off Christian to pack back the Caribbean batsman.
Comfortably placed at 117/4 after 14 overs, the stage was set for Nair and New Zealander Corey Anderson (3) to step up the gas after the second time out.
But Dhoni's brilliance behind the stumps foiled Delhi's plans, when the former India skipper effected a perfect stumping to end Anderson's five-ball stay.
Despite losing his partners at the other end, Nair, who had faced 37 balls by then completed his half century and was joined briefly by Pat Cummins (11), before Stokes packed back the Australian.
Towards the end, veteran leggie Amit Mishra (11 not out) joined Nair to add a quickfire 22-run stand for the seventh wicket before the Karnataka batsman got a top edge off Stokes to be caught by Jaydev Unadkat at midwicket.
Unadkat bowled a brilliant final over, leaking five runs and taking the wicket of tailender Mohammed Shami (2) as the home side failed to get the push.
Brief Scores: Delhi Daredevils 168/8 (Karun Nair 64, Rishabh Pant 36, Marlon Samuels 27, Ben Stokes 2/31) vs Rising Pune Supergiant.