The German was hauled up for an incident during the closing stages of qualifying that compromised Hamilton's final hot lap.
On provisional pole position by just 0.059secs from Hamilton after the opening quick laps, Rosberg locked up on the entry to Mirabeau on his second and final attempt, and was forced to take the escape road.
An attempt to reverse swiftly brought out the yellow flags. The championship leader, behind and on a quicker lap, was forced to abort, denying him top spot on the grid.
Hamilton later inferred Rosberg's actions were deliberate, but during a surprisingly swift hearing, Rosberg was found not guilty.
A statement said: "The stewards examined video and telemetry data from the team and the FIA and could find no evidence of any offence related to the turn five [Mirabeau] incident."
A spicy duel now looms between the duo after Mercedes' third front-row lock-out of the season. Asked: "Did he [Rosberg] screw you over?", Hamilton replied: "Potentially."
When a similar was question was put to him, Hamilton responded: "I'm not saying no."
Such words are likely to enrage Rosberg and it is clear bridges have been burned between the title chasers, with Hamilton referencing the bitter hostilities between his hero Ayrton Senna and Alain Prost which began when the Brazilian and the Frenchman were team-mates at McLaren in the late 1980s.
Senna and Prost twice collided on the track at the Japanese Grand Prix at crunch points in the 1989 and 1990 championships, with Senna admitting he took Prost out on purpose in 1990.
"I don't know if Senna and Prost talked about it, but I quite liked the way Senna dealt with that, so I'll take a page out of his book," Hamilton said.
Throw in the Briton's remarks earlier last week when he suggested his under-privileged upbringing on a council estate in Stevenage in comparison to Rosberg's Monaco-based childhood made him hungrier to succeed, and the touchpaper has been lit for fireworks on the streets of the principality.
Mercedes motorsport boss Toto Wolff was adamant he can continue to manage the pair. He strongly defended Rosberg ahead of the stewards' hearing, saying: "I don't think anybody does that deliberately in modern Formula One.
"He missed his braking point, which was in order to beat his team-mate, and he took the exit. That's it. There is nothing to add."
He now has a far-from-happy Hamilton on his hands, but Wolff added: "Of course, we'd like to have two happy drivers, but if you are as competitive as they are in a car capable of winning the world title, every weekend you are going to have one happy and the other unhappy.
"There is no difficulty in managing this sit-uation. We spoke to them in the debrief and it was all OK, all good."