Warner (54) and Rao (60) put on a 83-run partnership for the fifth wicket as Daredevils, from 29 for two in five overs and 36 for four in eight, rallied to cross the 100-run mark at the Sawai Man Singh stadium.
Warner struck six fours and a six in his 44-ball innings, while Rao hit four fours and as many sixes during his 40-ball stay to lift Delhi from a precarious situation.
Earlier, electing to bat, Daredevils were off to a dismal start losing two wickets in the form of skipper Virender Sehwag (4) and Aaron Finch (11) inside the first six overs.
Sehwag`s decision to bat on a placid Jaipur track backfired as Rajasthan`s Australian import Shaun Tait struck early to leave the visitors reeling at 30 for 2 in six overs.
Tait, who replaced injured New Zealander Jacob Oram in the side, dismissed the dangerous Sehwag in his first over.
The India opener, who hit Tait for four through cover point off his second ball, created room for himself on the very next delivery only to edge the ball, which Dravid pouched effortlessly at first slip.
Next man-in, Finch, hit the first six of Delhi innings when he clobbered South African spinner Johan Botha over wide midwicket in the third over to somewhat break the deadlock.
But his exploits soon came to an end when the Australian responded late to a bouncer from Tait, lobbying a simple catch to Botha at mid-on.
The experienced speedster mixed aggression with pace as he used the windy conditions to devastating effect.
Skipper Warne introduced himself in the eighth over and spun a web around Delhi`s batsmen as he dismissed Unmukt Chand (2) and Naman Ojha (0) in quick succession.
Warner and Rao then came together and did the repair work as they took the score past 50-run mark in 10.4 overs.
They steadied the ship for the Delhi team, which had started the tournament with a big defeat to Mumbai Indians.
Warner reached his half century off 40 balls, while Rao a little quicker, at 37 balls.
After Warner departed, caught by Abhishek Raut off pacer Amit Singh in the 18th over, Rao punished the Rajasthan bowlers, especially Siddharth Trivedi, clobbering him for two huge sixes.
But Trivedi had the last laugh as Rao was caught by Warne at deep midwicket off Trivedi`s slower one.
Irfan Pathan (9) hit Tait for two consecutive fours in the last over to take Delhi past the 150 mark.
Besides Tait and Warne, Amit Singh and Siddharth Trivedi bagged a wicket each.