Rosberg led all 78 laps on the 2.1-mile Monte Carlo street course, notching his second career grand prix victory following his 2011 victory in China.
The Monaco resident -- whose father Keke Rosberg won the event in 1983 -- held off defending Formula One champion Sebastian Vettel down the stretch, beating him by 3.888 seconds at the finish line.
The race was delayed 20 minutes at one point to make repairs to a wall after a crash involving Pastor Maldonado.
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