Mo Salah continued his breathtaking form to become the first opposition player to score a Premier League hat-trick at Old Trafford, with Diogo Jota and Naby Keita also on the scoresheet.
The result puts pressure on United boss Ole Gunnar Solskjaer, who called it “the darkest day” and said his side had hit “rock bottom”.
However, Ronaldo, who had a potential consolation from VAR, took to social media and insisted the players take responsibility.
“Sometimes the result is not what we are fighting for. Sometimes the score is not what we want. And it’s up to us, only us, because there’s no one else to blame, ”Ronaldo wrote on Instagram.
“Our fans have been, once again, amazing in their continued support. They deserve better than that, much better, and it’s up to us to deliver them. It is now!”