MELBOURNE (AFP, REUTERS) - Nico Rosberg led a Mercedes one-two as he won the season-opening Australian Grand Prix in Melbourne on Sunday, crossing the line 8.3sec ahead of team-mate and world champion Lewis Hamilton.

Former four-time world champion Sebastian Vettel finished third for Ferrari, having jumped the Mercedes pair at the start and leading until his final pit stop.

Rosberg won a dramatic Grand Prix for Mercedes after Ferrari's challenge was squandered by a bungled tyre strategy and Fernando Alonso walked away from a spectacular crash that reduced his McLaren to a mangled wreck.

His 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, 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 tyre management, especially after Alonso's crash brought out a red flag, as his compatriot Rosberg coasted home.

New team Haas celebrated points on debut, with Frenchman Romain Grosjean finishing sixth behind Red Bull's Daniel Ricciardo and Williams driver Felipe Massa.

Manor driver Rio Haryanto retired early with car trouble.