Cristiano Ronaldo scored his 800th career goal before driving home a penalty winner as Manchester United came from behind to beat Arsenal in a memorable contest featuring two crucial VAR decisions.

Emile Smith Rowe drove home from the edge of the area, while United keeper David de Gea was lying on the ground, seemingly injured, with his back to play.

The inevitable VAR check concluded De Gea had fallen after bumping into and being trodden on by his own team-mate Fred, and referee Martin Atkinson gave the goal.

Bruno Fernandes levelled, when he finished off an intricate move involving Jadon Sancho and Fred a minute before the break, setting up the pulsating second half that followed.

Ronaldo put United ahead as he swept home Marcus Rashford’s cross, but Martin Odegaard made it 2-2 with a well-taken equaliser.

Then came the second big VAR decision, as Atkinson gave United a penalty after reviewing Odegaard’s challenge on Fred on a pitchside monitor – and Ronaldo kept his nerve to score.

Watching proceedings unfold, Rangnick was largely impassive and made plenty of notes, although he did stand to applaud Ronaldo’s winner.

The result leaves United three points off fourth-placed Arsenal after recording two wins and a draw under Michael Carrick, the interim’s interim.

Carrick, stand-in for the past three matches, said afterwards that he was leaving the club, where he has been since 2006, first as a player and latterly as a coach.

A controversial start to the scoring

There is an festering history between these teams, from the on-pitch brawl that led to both teams having points deducted in 1990, through the controversy in which Arsenal players jumped at Ruud van Nistelrooy after he missed a last-minute penalty in 2003, to the infamous ‘pizzagate’ incident, which led to Sir Alex Ferguson conducting his post-match interviews in a change of clothes after being hit by food thrown from the visitors’ dressing room in 2004.

Now there is another infamous moment to add to the list.

In law, Atkinson had no choice but to award Arsenal’s opening goal, having waited to blow his whistle until Smith Rowe’s shot hit the net.

United’s players clearly felt the situation, with De Gea on the floor with his back to play, warranted a stoppage.

They surrounded Atkinson in their immediate protests and at half-time, De Gea continued, with technical director Darren Fletcher, currently assisting on the coaching side, pitching in as the official reached the mouth of the tunnel.

Amid all the furore, Arsenal were probably unhappy not to be ahead at that stage – having lost their lead just before half-time after controlling a large part of the game. By the end, they must have wondered how they ended up with nothing.

De Gea saved superbly twice from Pierre-Emerick Aubameyang and also denied substitute Bukayo Saka, who also had a goalbound effort deflected wide.

Rangnick’s issues

Rangnick is scheduled to speak to the media for the first time on Friday morning before he gets to work before his first game in charge against Crystal Palace on Sunday.

He didn’t need to watch this to know some of the issues that need resolving.

Fred was not great in that opening period, Harry Maguire and Victor Lindelof were unconvincing in central defence, and Ronaldo and Fernandes do not press in the modern manner.

What Ronaldo, in particular, does is score goals. Lots of them.

There is the Czech football association’s claim that Josef Bican scored 821 career goals. And there are further claims – also unverified – that Brazilian pair Pele and Romario both scored more than 1,000. But officially, no-one has ever scored as many as Ronaldo.

The notes Rangnick made throughout the game probably didn’t include a simple ‘I need to get the best out of my new number seven’ but if he can, within a team structure that performs to the sum of its parts rather than the mess it turned into during the final two months of Ole Gunnar Solskjaer’s reign, United’s results will improve.

A banner was unfurled in Solskjaer’s honour before kick-off but it is one of his coaches who has stabilised the situation. Now Rangnick follows David Moyes, Louis van Gaal, Jose Mourinho and Solskjaer in trying to make United winners again.

Manchester United are next in action against Crystal Palace on Sunday, 5 December (14:00GMT). Arsenal play at Everton on Monday, 6 December (20:00GMT).