By Ian Ransom
MELBOURNE (Reuters) - Nico Rosberg won a dramatic Australian Grand Prix for Mercedes on Sunday after Ferrari's challenge was squandered by a bungled tire strategy and Fernando Alonso walked away from a spectacular crash that reduced his McLaren to a mangled wreck.
Rosberg's 15th career victory was also his fourth in succession after the German won the final three races of last season.
His team mate and pole-sitter Lewis Hamilton finished second, some eight seconds behind after recovering from a chaotic start that pushed the defending world champion back to sixth at the first turn.
Ferrari's Sebastian Vettel led for much of the race but his advantage was eroded by poor tire management, especially after Alonso's crash brought out a red flag, as his compatriot Rosberg coasted home.
"Yeah! awesome, guys, awesome. Great start to the season," Rosberg yelled down the team radio.
New team Haas celebrated points on debut, with Frenchman Romain Grosjean finishing sixth behind Red Bull's Daniel Ricciardo and Williams driver Felipe Massa.
(Editing by John O'Brien)