Ole Gunnar Solskjaer appeared to salute towards Manchester United's legendary manager Sir Alex Ferguson after Scott McTominay scored at the death to seal a 2-0 win over Manchester City on Sunday.
The Norwegian became the first Red Devils boss since Fergie to do the double over their bitter rivals - the first time they had done so in a decade.
Anthony Martial gave the home side the lead when Ederson allowed his weak volley past him in the first half. United then withstood a second-half onslaught from the Premier League champions before City's stopper made his third error of the derby.
With rain pouring down on the Old Trafford playing surface, Ederson overcooked a throw which went straight to McTominay around 35 yards from goal.
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