Argentine superstar Sergio Aguero reportedly punched a Wigan fan in a post-match fracas as Manchester City were sensationally knocked out of the FA Cup by third-tier Wigan Athletic 1-0 on Monday in a stunning fifth round upset with a late goal by their talisman Will Grigg.

On a magical night in the world's oldest cup competition, Wigan's folk hero Grigg secured one of the biggest shocks by slotting the ball home from the edge of the box in the 79th minute after a misjudgement by City substitute Kyle Walker.

The now-familiar chants of 'Will Grigg's on Fire', a hit download two years ago, echoed around the DW Stadium.

The visitors had played the entire second half with 10 men after their midfielder Fabian Delph was sent off in the 45th minute for a sliding challenge on Max Power.

The defeat was City's third of the season and ended their hopes of an unprecedented quadruple of trophies this campaign.

Their manager Pep Guardiola said his expensively-assembled side had done everything but paid the price for one mistake.

"That kind of game is like a final and always the teams can punish you," he told the BBC. "OK. So accept the defeat. Congratulations to Wigan," added the Spaniard, whose side enjoyed 82 percent of possession in the second half.

"These kind of games, when you have 10 against 11, maybe you cannot score a goal. They defended well, they are at the top in League One."

Stirring Memories

Wigan will host another Premier League team Southampton in next month's quarter-finals having now beaten three top-flight sides in their fairytale Cup run.

"It feels great, doesn't it," said their manager Paul Cook. "It's such a severe test, they're such a strong side... tonight we had to ride our luck at times. The sending off is always a big incident in the game.

"But that's what makes the FA Cup so special. Our lads deserve a lot of credit tonight for the amount of work and the levels of energy they put in."

On a night of stirring memories for the home fans, whose unfancied side beat City in the 2013 FA Cup final and also in the quarter-finals a year later, there was always electricity and the hint of a shock in the air.

That only increased when referee Anthony Taylor, a yellow card already in his hand, reached for the red.

Delph looked stunned, his angry team mates swarming around the official, while Guardiola seethed on the touchline.

The Spaniard, already frustrated by his side's failure to break through the hosts' sturdy defence, had to be kept apart from Cook as they headed down the tunnel at the break.

"There's no problems," said Wigan's Cook. "He's an outstanding manager. We hope he goes on and wins Champions Leagues and Premier Leagues because they deserve that."

Guardiola Reacts

Guardiola reacted to the setback of going down to 10 men by bringing on versatile right back Kyle Walker for winger Leroy Sane at the start of the second half.

He then introduced midfielder Kevin De Bruyne in place of David Silva in the 65th, with the Belgian immediately piling the pressure on Wigan's defence.

But still City, 16 points clear at the top of the Premier League, heading for the last eight of the Champions League and looking forward to Sunday's League Cup final against Arsenal, failed to find a way through.

Walker then let the ball run past him without realising Grigg was lurking to seize the chance to finish with a flourish.

"I'm scoring every week now so it's nice and easy," the Northern Ireland international, now the competition's top scorer with seven goals, said jokingly.

"I caught the offside trap and it was a nice little race with Kyle Walker. I am a goalscorer, if I get a chance I'll score them. The FA Cup has been brilliant to me." 

Aguero punches fan

Aguero appeared to throw a punch during an altercation with Wigan fans following the defeat. The Argentine striker was surrounded by Wigan supporters who flooded onto the pitch after their shock victory.

TV cameras captured Aguero tussling with one fan in particular before swinging his arm at the Latics supporter. Aguero was held back by Wigan and City players before being escorted away from the pitch.