Surviving on just two pit stops, the 2007 world champion clung on to win by 12.4 seconds from the Ferrari of Fernando Alonso with triple world champion Sebastian Vettel third.
Raikkonen, who also won at Albert Park in his title-winning year, sent out a message that Lotus was set to fight for the Formula One championship, rather than be the outside hope it was last year.
The Finn's teammate Romain Grosjean also finished in the points, crossing the line in 10th spot.
Mark Webber's chances were again ruined by his trademark slow start.
After qualifying in second spot, the veteran was swamped when the lights went out, a sitting duck for those behind.
Before the end of the opening lap, the Australian had dropped from second to seventh place, his hopes left in tatters.
Vettel had no such issues, leading from pole position as the Ferraris of Felipe Massa and Alonso swept past Webber into second the third spots respectively.
Lewis Hamilton's Mercedes dropped a spot to fourth while Raikkonen filed into fifth place.
Vettel grabbed two early pit stops and a third on lap 28 but was outfoxed by Alonso.
But when the Spaniard pitted a third time, Raikkonen inherited the lead and managed to preserve his tyres against the odds until the chequered flag.
At the start, Nico Rosberg had also managed to sneak past Webber but was hit by mechanical gremlins midway through the race, his Mercedes drifting to a halt on lap 27 off the track.
Two laps earlier, Pastor Maldonado ended his hopes when an unforced spin left his Williams stuck in a safety trap.
Australian Daniel Ricciardo's race lasted until lap 42 when his Torro Rosso was hit by mechanical issues and was pushed back into the garage.