Danilo unleashed a rocket before Aaron Ramsey and Cristiano Ronaldo finally broke 10-man Sassuolo in a hard-fought game.
Pedro Obiang saw red approaching half-time for his studs-up tackle on Federico Chiesa’s ankle.
It took a ferocious strike from Danilo to break the deadlock, but Gregoire Defrel and his team would not give up, grabbing a deserved equaliser.
Sassuolo even tried to win it, but Ramsey met a Gianluca Frabotta ball rolled across the six-yard box.
Cristiano Ronaldo left it to the last second of the game to grab his goal, running on to a long Danilo ball.