Ricciardo's exclusion from the results tarnished what had been a day of celebration for local fans, who were jubilant that the Red Bull driver had apparently become the first Australian to finish on the podium at his home race.
However just before midnight, stewards ruled that Ricciardo's car had "exceeded consistently the maximum allowed fuel flow" and that the team refused an instruction from the race's technical delegate Charlie Whiting to change the fuel-flow sensor before the race and a further request during the race to reduce the fuel flow.
Red Bull immediately announced it would appeal the decision.
"Inconsistencies with the FIA fuel flow meter have been prevalent all weekend up and down the pit lane," a Red Bull statement said. "The team and (engine supplier) Renault are confident the fuel supplied to the engine is in full compliance with the regulations."
The exclusion capped a day of shocks at the Albert Park street circuit.
Thought Rosberg's victory was little surprise, given Mercedes had been the dominant team in preseason testing and across the race weekend in Melbourne, few would have expected pole sitter Lewis Hamilton and defending four-time world champion Sebastian Vettel to be mere onlookers after half a dozen laps.
Both Hamilton and Vettel suffered engine failures, illustrating the difficulties all teams are having getting performance and reliability out of the sport's new V6 hybrid engines.
Ricciardo's disqualification meant Kevin Magnussen was promoted to second in his debut race, ahead of his McLaren teammate Jenson Button, giving the team a bright start to the season and the lead in the constructors' championship after a very disappointing 2013.
Rosberg started third on the grid and was first to reach turn one, then drove away from the field to eventually win by 24.5 seconds at the Albert Park street circuit. The margin of victory and the authority of the performance showed why Mercedes is considered a strong favorite to finally win its first constructors' title this season.
"I had an unbelievably quick car today," said Rosberg, whose world champion father Keke won the inaugural Australian F1 GP in 1985. "It was such a pleasure to drive, it's such a great feeling and I really look forward to the new races."
Rosberg's delight was a contrast to the disappointment on the other side of the garage as Hamilton quickly retired a car that was only firing on five cylinders.
"We looked so strong but to then have a hiccup is tough for everyone, but we will bounce back," Hamilton said.
Like Mercedes, Red Bull was on one hand celebrating a strong performance in the opening race while also harboring concern about the engine problems that caused the retirements of their top drivers.
"We learned the car is quick, we just need to get everything together," Vettel said. "No doubt we'll fix this issue, the question is how soon?"
Ferrari's Fernando Alonso finished fourth in a worryingly uncompetitive performance for the Italian team, while Williams driver Valtteri Bottas recovered from losing a wheel early in the race to finish fifth; pulling off a succession of impressive passing moves that showed the strong potential of the car.
Force India's Nico Hulkenberg and Ferrari's Kimi Raikkonen — in his return to the team after six years away — finished sixth and seventh respectively, ahead of the Toro Rosso pair Jean-Eric Vergne and Daniil Kvyat. After Ricciardo's exclusion, Force India's Sergio Perez was promoted to the final points-paying position in 10th.
The 19-year-old Kvyat's 10th place made him the youngest driver ever to earn an F1 point, breaking Vettel's record set at the 2008 Italian Grand Prix. The 21-year-old Magnussen was the second-youngest driver to claim a podium finish, behind Vettel's record at the 2007 U.S. Grand Prix.
Despite fears that few cars would complete the race due to a series of reliability problems in preseason testing and over this weekend, 15 of the 22 racers finished. There was only one major accident, with Caterham driver Kamui Kobayashi slamming into the back of Felipe Massa's Williams at the first corner, immediately ending the race for both drivers.
Magnussen's heady performance for a rookie driver illustrated why McLaren put such faith in him, discarding Sergio Perez after a single season to make room.
McLaren leads the constructors' championship after one race; an impressive recovery after a dire 2013 season in which the high-achieving team failed to secure a single podium.
"It's not a win but it feels like a bit of a win," Magnussen said. "The team is coming off a difficult season and they just wanted to come back.
"The team is massively motivated to stay on top and they are a team that should be on top in Formula One."
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