Premier League leaders Arsenal have had their title credentials questioned all season but their last-gasp 3-2 win against Manchester United has silenced many of the remaining doubters.

(Photo: AFP)

Eddie Nketiah scored the winner in the dying moments of a pulsating match at the Emirates on Sunday as the home fans were infused with fresh belief that this could be their year.

The game against in-form United was seen as a critical test for the Gunners, especially after Manchester City closed the gap at the top of the table to just two points earlier in the day.

It was a challenge they did not fluff, hitting back hard after conceding the first goal, scored by Marcus Rashford, and staying calm after Lisandro Martinez cancelled out Bukayo Saka's strike in the second half.

Arsenal, who have made their best-ever start to an English top-flight season, now have 50 points after 19 games -- five clear of defending champions City with a game in hand at the halfway point of the campaign.

"I don't think it gets much better than that," said a buoyant Arsenal coach Mikel Arteta.

"It was a beautiful moment, a really special one because we were pushing and pushing and pushing and the goal wasn't coming and it came at the end... it was just electric. It was really emotional, really passionate and I lost it."

Arteta said he hopes the result, which follows last week's 2-0 win against Tottenham in the north London derby, gives his team the belief that Arsenal can be crowned league champions for the first time since 2004.

But he wants to keep his team's feet on the ground despite a remarkable season in which they have lost just once in the league.

"We know our reality, we know how much we still have to improve," said the Spaniard, who was previously Pep Guardiola's assistant at City.