What happened? In simple terms, we got our numbers wrong."
Briton Hamilton did not look happy, walking slowly and despondently out of his car with his head down. "I can't really express the way I feel at the moment, so I won't even attempt to," he said.
Rosberg, who won the Spanish GP two weeks ago, is now just 10 points behind after securing back-to-back wins for the first time in his career. Four-time F1 champion Sebastian Vettel is less of a threat, but the Ferrari driver finished second to close the gap on Hamilton to 28 points heading into the Canadian GP in two weeks.
As well as securing his 10th career win, Rosberg became the first driver since Ayrton Senna to win Monaco three straight times.