Manchester United manager Jose Mourinho praised a "world best" display by goalkeeper David de Gea after his side's hard-fought 3-1 win away to Arsenal on Saturday.

Victory left United five points adrift of Premier League leaders Manchester City, who will go eight points clear again if they beat West Ham on Sunday, ahead of next week's Manchester derby.

But the win was far from routine even though early goals from Antonio Valencia and Jesse Lingard put United 2-0 up at the Emirates Stadium as soon as the 11th minute.

De Gea made several brilliant saves before Arsenal eventually pulled one back through Alexandre Lacazette four minutes after half time.

But Lingard's second goal in the 63rd minute eventually made the game safe for the visitors before United midfielder Paul Pogba was shown a straight red card for a studs-up challenge on Hector Bellerin.

It was De Gea, however, who Mourinho singled out for special praise, telling BT Sport: "I told him after the match, what I saw today was the best from a goalkeeper in the world.

"You need the keeper to be there for you when the team needs," the Portuguese boss added. "All the effort from the players was magnificent."

As for Pogba's dismissal, which will rule him out of the Manchester derby, Mourinho said Arsenal had been fortunate not to go a man down as well following a challenge by Laurent Koscielny on Romelu Lukaku.

"I don't know," he said. "I leave for you the Lukaku situation with Koscielny, I leave for you the Arsenal players on the grass. The grass is absolutely beautiful -- I think there is a desire to go onto the grass."

There was no hiding former Chelsea manager Mourinho's joy, however, at an impressive all-round United display.

"I loved the way my team played and fought," he said. "Arsenal played in some periods amazing attacking football -- creating difficulties for us.

"But I have to say that my players deserve all the great words. I don't know so many in English but amazing, phenomenal, fantastic. They deserved three points."

For Arsenal manager Arsene Wenger, who has had an often fractious relationship with Mourinho, there was pride in the way his side recovered from a horror start but ultimately a sense of frustration at their failure to take anything out of the game.

"I think we didn't start well at all at the back and we are guilty of that," Wenger told the BBC.

"Despite being 2-0 down we should have come back -- we had enough chances. We produced excellent quality, but were not decisive enough," the veteran French boss added.

"It was a mystery yes (not scoring more goals), but David de Gea was man-of-the-match by a clear mile.

"We played well but there is nothing more frustrating when you have that quality of performance and nothing to show for it at the end.

"The attitude was impeccable until the end. But you cannot make the mistakes we made at the beginning."

Pogba was sent off in the 74th minute of United's 3-1 win at Arsenal on Saturday for a crude challenge on Hector Bellerin.

Koscielny responded to the foul by approaching referee Andre Marriner and appearing to call for Pogba's dismissal.

Pogba sarcastically applauded Marriner as he headed for the tunnel and United boss Mourinho made it clear the France star wasn't happy with the decision or his international team-mate's part in it.

"I just know that Paul is frustrated. A bit disappointed with this colleague, Koscielny, with this kind of reaction," Mourinho said.

"He is very frustrated because everybody knows that Paul is a clean player and it was not his intention at all to be close to a red card."

Danny Welbeck and Alexandre Lacazette, appealed in vain for penalties and, with his tongue firmly in his cheek, Mourinho said: "I know the pitch is amazing and maybe breeds a desire to go to the floor.

"If it was hard, no; if it was mud, no - the pitch is absolutely beautiful but I think they were a bit too much.

"If it's not a penalty, it's not a penalty."

Pogba's dismissal will earn him a three-match ban and his absence from the Manchester derby is a huge blow to United's hopes of closing the gap on the leaders.

City are five points ahead of United, but can extend that lead to eight if they beat lowly West Ham on Sunday.

Regardless of that result, United will remain in the title hunt when their hated neighbours arrive at Old Trafford next weekend.

But Mourinho refused to label the seismic showdown as a make or break moment in the title race.

Asked if United's fourth successive league win had sent a message to Pep Guardiola's team, he said: "No message. We go match after match.

"We are second in the table. We won four consecutive matches.

"We managed to win and play well. I'm happy but there is no message."

- Desire and intensity -

While Mourinho was coy about the derby, he was effusive in his praise of his players after they won at the Emirates for the first time since 2014, ending their long run of futility in away league games against top-six opponents.

"We started with that desire and intensity, we played high and created mistakes," he said.

"There were amazing individuals performances and collectively we were very strong."

United were indebted to David De Gea for a superb display, the Spaniard making 14 saves, the joint most by a goalkeeper in the Premier League era.

"He made fantastic saves," Mourinho said. "What I saw was the best goalkeeper in the world."

Inevitably, Arsenal boss Arsene Wenger saw the two penalty appeals differently to his old rival and he took a swipe at Marriner's performance.

"Last night I watched Napoli v Juventus on TV and we watched a top-class referee. If you want to analyse well, watch the difference between them and us and then you will see," he said.

Even so, Wenger acknowledged Arsenal had only themselves to blame for a loss that effectively ended their title bid.

Antonio Valencia and Jesse Lingard punished terrible Arsenal defending to put United two up in 11 minutes.

Lacazette got one back but Lingard's second sealed the points.

"You have to dictate from the start and show strength in duels from the back," Wenger said.

"I felt that at the back our concentration was not sharp enough from the start and not dominant enough.

"We have produced an excellent performance but have conceded three goals and had at least 10 chances and were not efficient enough in the box, that is the reality."