Juventus beat Manchester United 1-0 at Old Trafford to take command of Champions League Group H with a maximum nine points.

Paulo Dybala’s 17th minute goal, a simple conversion after a low cross from the right by former United man Cristiano Ronaldo, won the game but the dominant Italian champion could have clinched it by a much more convincing margin. United needed its Spanish keeper David de Gea to be in top form as he made a series of good saves, including an excellent effort to keep out a second half strike from Ronaldo.

With four points leaving it second in its group, ahead of Valencia and Young Boys, United may still progress to the knockout stages but the gulf between it and a team equipped to reach the latter stages was all too evident. United was unchanged from the team that drew at Chelsea in the Premier League but the visitor very quickly demonstrated that it had no fear of the task in front of it.

Right from the outset, Massimiliano Allegri’s side was sharper, faster, more precise and showed more purpose than Mourinho’s men. The most disconcerted Juve looked in the early exchanges was when a fan invaded the pitch only to be apprehended by security before he could reach his apparent target Ronaldo. It was no surprise at all when, in the 17th minute, Juve took the lead. Ronaldo broke down the right and put in a low cross towards the near post, which Chris Smalling and Juan Cuadrado challenged for before the ball fell kindly to Dybala, who converted with ease. Juve sensed the fear in its opponent and looked for a quick second as Joao Cancelo burst unchallenged into the area and then tested United’s De Gea with a fierce drive. It was a busy opening half for the Spanish keeper — Ronaldo struck a swerving free-kick straight at De Gea, who then did well to keep out the follow-up effort from Blaise Matuidi.

Ronaldo brought another fine save from De Gea seven minutes after the interval with a thundering shot after being set up by Cuadrado. United could have drawn level in the 75th minute when Paul Pogba, facing his former club, struck the post with a shot from outside the box. At the final whistle, a fan tried to greet Ronaldo and came up against security officers but the Portuguese insisted on taking a photograph with the interloper and left the field to the applause from both sets of fans.

United fans were left with a reminder of their glorious past in the shape of Ronaldo. It was their only consolation after a game in which their current weaknesses were so comprehensively exposed.