Amad Diallo scored twice to breathe life into Manchester United's Europa League campaign with a morale-boosting 2-0 victory over Greek champions PAOK Salonika at Old Trafford.

Ruud van Nistelrooy, in his third game as interim boss, handed Amad his first start in over a month - and the 22-year-old repaid his faith with a vibrant performance that was capped by two decisive second-half strikes to ignite United's hopes of progressing to the knockout stages.

United had drawn their opening three Europa League encounters against Twente, Porto and Fenerbahce and it was vital that they got off the mark against a PAOK side who had the better of the first-half chances. Andre Onana produced fine saves to deny both Mady Camara and Andrija Zivkovic.

In contrast, United only fleetingly threatened Dominik Kotarski's goal in the opening 45 minutes with Rasmus Hojlund's tame header from Casemiro's cross easily kept out before a brilliant piece of last-ditch defending from Baba Rahman denied Amad at the far post.

Greater urgency was demanded from the restart, and within five minutes United were in front as Amad rose to meet Bruno Fernandes' deep cross to loop a header back across goal and in off the far post.

United were nearly unpicked immediately as Taison fed the unmarked Tarik Tissoudali, but the PAOK striker telegraphed his shot from point-blank range. It enabled Amad to put the seal on a victory for Van Nistelrooy with a determined run and finish which will do his chances of featuring under incoming head coach Ruben Amorim no harm (77).

The victory moved United up to 15th as the 36-team league phase reached the halfway point, with their next Europa League match against Bodo/Glimt being Amorim's first match at Old Trafford.

Van Nistelrooy told TNT Sports: "Amad made a difference today, because of his goals but he was very sharp. Well done to him, good game. Positionally we weren't good in the first half. We were much better at that in the second half.

"He has been incredible in training, he always trains well and is asking me to do more."

How Diallo dazzled in early Amorim audition

United had won just one of their last 11 European games and the Greek champions were no pushovers.

The 4,000 fans in the away end - plus a number in the home section - held their breath early on after Camara's shot was blocked by Casemiro, wrongfooting Onana before being dealt with.

Zivkovic bent well wide after making himself space as the chorus of PAOK chants continued and United began asking questions of their own.

Van Nistelrooy's side started sending balls into the box and Alejandro Garnacho saw a shot blocked shortly after the VAR checked for a potential penalty.

Diallo went down having been caught by former Chelsea left-back Rahman, but referee Radu Petrescu's decision to ignore the appeals were ratified by Daniele Chiffi in the booth.

Hojlund saw a bundled header gathered by Kotarski having met a cross from Diallo, who saw the ball taken off his toe by Rahman after Garnacho whizzed a low ball to him at the far post.

PAOK showed increasing threat as the opening period wound down. Onana stopped Zivkovic's hopeful attempt and then tipped over Camara's snapshot after a fine first touch.

Neither side made a change heading into a second half that was five minutes old when Amad broke the deadlock.

Bruno Fernandes sent a diagonal ball to the far post, where the winger stretched to send a looping header back across goal and just inside the post.

PAOK claimed Hojlund had impeded Tomasz Kedziora's attempt to clear, but it was given the green light after a VAR check.

Diallo was denied a second by Kotarski as United played with intent but without the requisite incision. That has been costly for United this term and Zivkovic lasered narrowly wide before PAOK blew a glorious 64th-minute chance.

Tissoudali's glaring miss was a let-off for Van Nistelrooy's side, who calmed the nerves with a fantastic 77th-minute goal.

Amad won possession as he continued his battle with Rahman, showing strength then skill as he moved on to his left foot and curled home a fine effort from the edge of the box.

Mason Mount came on after the match-winner appeared to pick up a knock, with the visitors then bringing on Shola Shoretire.

The United academy graduate remains the youngest player to feature for the Red Devils in a European game and was applauded on to the field by the home support. Marcus Rashford went close to adding gloss in stoppage time.

Van Nistelrooy added: "It was a pretty poor first half if I'm being nice. The second half way was better. That was clear. For me it was important to get results. I can only be happy with the performance that the players put in.

"I enjoy it but Sunday is another one and I'm so focused on doing that so I'm not thinking of what is next."

Amad has to start against Leicester

Sky Sports' Ben Grounds:

From the first whistle, there was an edge to Amad. Overlooked towards the end of Erik ten Hag's reign, here he demonstrated an application both with and without the ball those wanting to play in his position must look up to as an example to follow.

He will have certainly caught Amorim's eye on his first start in five weeks, with the lively winger denied a penalty despite appearing to be caught by Baba Rahman in a forgettable first half.'

He continued to prove a thorn in the side and fantastically guided home a header before settling nerves with a beautiful curling effort from distance after winning the ball.

Against PAOK, he helped himself to his first ever brace for United, with five of his six goals in all competitions for his side coming at Old Trafford.

His opener was just his second goal in major European competition, also netting a header assisted by Bruno Fernandes for United against Milan in March 2021 in the Europa League.

For Amorim, it is a combination that could prove very fruitful provided Amad uses this performance as the benchmark moving forward.

Amad: I just want to make people happy

This was just Amad's second start in nine matches. He took the applause from the supporters barefoot having been withdrawn as a precaution towards the end. But nothing could wipe the smile off his face.

"It's been a long time since we won in Europe," he told TNT Sports. "Today we showed why we are one of the best teams. It was important to win today. It is important to score every time. This season I have been unlucky so I am happy to score two today. But the most important thing was to win.

"I like to celebrate with the fans and make people happy."