Manchester United make it four from four on another night to forget for Benfica youngster Mile Svilar

Manchester United 2 Benfica 0: Nemanja Matic's first-half strike was deflected in off the Belgian goalkeeper while Daley Blind converted from the spot to secure victory

Daley Blind celebrates after converting from the spot to double the hosts' lead (Getty)

The youngest goalkeeper in Champions League history is now the youngest player to score an own goal in the competition too. Most who play in Mile Svilar’s position go their whole career without suffering the indignity that Benfica's 18-year-old suffered here, but Manchester United seem to know how to expose the talented teenager's lack of experience.

Two weeks after being bullied and brutalised in Lisbon, Svilar had another night to forget, if only because Nemanja Matic's speculative strike from range at the end of the first half cruelly deflected in off his back after hitting the upright. It was an unfortunate moment, not least because Svilar had done so well to deny Anthony Martial from the penalty spot with a smart save half an hour earlier.

Were it not for that moment of ill fortune, Benfica might feel they would have taken their first point in Group A against a pedestrian United. The hosts were not at their best here by any means, with only Martial and substitute Marcus Rashford offering much in attack, but after their fragile lead was extended by Daley Blind's late penalty, this unspectacular display proved enough for a fourth Champions League win in four games.

Martial saw his penalty saved by Benfica's young goalkeeper (Getty)

Mourinho’s men began the night knowing that a victory could book their place in the knockout phase, but CSKA Moscow’s win in Basel means they must wait. Even so, with that prize on offer, Mourinho elected to name several second-string players in his starting line-up, with youngster Scott McTominay's inclusion the most surprising.

In the opening stages, to weaken the team that had beaten Tottenham Hotspur seemed like an error in judgement. Benfica, in need of points, were more than happy to play in United's half and started brightly, with Andreas Samaris and Raul Jimenez efforts threatening David de Gea’s goal.

Martial seemed like the only United player capable of similar invention and after one daring run into opposition territory, he forced a handball out of Benfica’s Douglas and won a penalty. The Frenchman confidently placed the ball on the spot but, after the targeting of two weeks' ago, Svilar took his vengeance, pushing the tame effort away.

Romelu Lukaku in action for United (Getty)

At the other end, the teenager's opposite number was forced into some heroics of his own. Benfica immediately carried on from where they had left off and a thunderous Diogo Gonclaves strike looked destined to open the scoring, only for De Gea to spectacularly meet it with an athletic, one-handed stop.

United needed to compose themselves and to their credit, they began to take the sting out of Benfica’s play, if still lacking any kind of threat in their own. Their breakthrough eventually came on the cusp of half-time and with a significant slice of luck. Matic, whose drive bounced in off Svilar’s back, once advised the half-Serbian youngster to join Benfica. ‘With friends like these…’

Svilar just about found time to deny Lukaku a confidence-boosting goal in added-on time at the end of the first half, smartly rushing out of his line to block the Belgian’s effort, but he still left for the dressing room dejected.

Eduardo Salvio attempts to get away from Eric Bailly (Getty)

If his head had dropped, those of his team-mates had not and Vitoria's players, to their credit, re-emerged with the same verve and threat they had shown at the start of the night. As United became increasingly complacent, Benfica grew in confidence and Diogo Gonclaves sent a chill around Old Trafford by riding Chris Smalling with ease then firing at De Gea.

The visitors went close again shortly after when, after Eric Bailly played a careless pass to Smalling, Jimenez nipped in to collect the loose ball and move through on goal. De Gea was beaten by his attempt, but it clipped the far post and went wide.

Benfica deserved to be at least level with a pedestrian United, though like in latter stages of the first half, they began to flag. The introduction of Marcus Rashford's incisive running at pace proved too much for their backline as the game drew on and it was the youngster who won United's second penalty of the game, leading to United's second goal.

Lukaku took the ball but Mourinho made certain that the he would not take it. Instead, the duty fell to Blind and this time, poor Svilar could not stop it.

Manchester United (4-2-3-1): De Gea; Darmian, Bailly, Smalling, Blind; Matic, McTominay; Mata (Herrera 68), Lingard (Mkhitaryan 45), Martial (Rashford 75); Lukaku.

Substitutes not used: Romero, Lindelof, Young, Shaw.

Benfica (4-3-3): Svilar; Douglas, Jardel, Ruben Dias, Grimaldo (Eliseu 64); Pizzi (Jonas 79), Fejsa, Samaris; Salvio, Jimenez (Serferovic 74), Gonclaves.

Substitutes not used: Julio Cesar, Lisandro Lopez, Zivkovic, Cervi.