On this day, May 11, 2013: Wigan stun Manchester City in FA Cup final

Watson's injury-time winner earned Latics a first major trophy in their 81-year history, with City manager Roberto Mancini facing the sack

Wigan players celebrate after beating Manchester City 1-0 to win the 2013 FA Cup final at Wembley on May 11. Getty

Dejected Manchester City players after conceding the late winner against Wigan. Getty

Wigan players celebrate victory at Wembley. Getty

Pablo Zabaleta of Manchester City is sent off by referee Andre Marriner. Getty

Goalkeeper Joe Hart and Sergio Aguero of Manchester City look on as Ben Watson's header hits the back of net to earn Wigan victory. Getty

Managers Roberto Mancini, left, of Manchester City and Wigan's Roberto Martinez. Getty

Carlos Tevez of Manchester City skips past Wigan's Antolin Alcaraz. Getty

City's David Silva of Manchester City on the attack against Wigan. Getty

Carlos Tevez attempts an overheard kick for City. Getty

City striker Sergio Aguero evades the challenge of Wigan's Paul Scharner. Getty

One shot on target in 90 minutes was all it took for Wigan Athletic to produce one of the great FA Cup final shocks.

Following in the footsteps of Sunderland in 1973, Southampton in 1976 and Wimbledon in 1988, the Latics sealed their place in the famous competition's folklore by claiming an unlikely scalp at Wembley Stadium on May 11, 2013.

Manchester City were the reigning Premier League champions – although arch-rivals United were about to take their crown – and sitting second in the table. Wigan were in the relegation zone and facing the drop with two games left to play.

But all was not well in the City camp. On the morning of the match, reports had emerged that manager Roberto Mancini was set to be sacked and replaced by Malaga's Manuel Pellegrini.

Ahead of the game, Mancini admitted that even winning the cup might not be enough to save his job.

“I won seven trophies in four years at Inter [Milan] and they sacked me after four years," he said. "This is football. I know football enough to understand this.”

Just to add to the surreal situation, Latics manager Roberto Martinez was himself being linked with a new job – replacing Manchester United-bound David Moyes at Everton.

Mancini had shown his ruthless streak ahead of the game by ditching Costel Pantilimon – City's FA Cup goalkeeper throughout their run to the final – and bringing in regular first choice Joe Hart.

It was a powerful City starting XI containing the likes of Vincent Kompany, David Silva, Carlos Tevez and Sergio Aguero. They had £27 million (Dh123m) Edin Dzeko, £26m James Milner and £15.8m Javi Garcia on the bench.

But it was Wigan winger Callum McManaman, who had joined the club on a free transfer after being released by Everton when he was 16, who walked away with the man of the match award after tormenting full-back Gael Clichy from start to finish.

City would have their chances – the likes of Yaya Toure, Tevez, Aguero and Gareth Barry all could have broken the deadlock – but lacked their usual fluency.

Defender Pablo Zabaleta's deserved red card for a second booking with six minutes to go would prove costly, as Wigan sealed a fairy-tale ending in injury-time.

Substitute Ben Watson had barely been on the pitch 10 minutes when he met a Shaun Maloney corner at the near post to head past Hart and send Wigan fans into ecstasy.

Watson, who had missed half of the season after breaking his leg, earned Wigan a first major trophy in their 81-year history.

"We were playing an incredible side. We didn't win by luck - from start to finish it was an incredible performance," Martinez said.

"The FA Cup is such a special tournament, and everyone deserves to feel proud today."

It was a very different story for Mancini, clearly furious at City for failing to quell speculation about his position.

He said: "You continue to speak about this for six months and also too much in the last two weeks. I don't know why the club didn't stop this because I don't think it's true."

Asked about reports that City had already agreed a deal with Pellegrini, Mancini added: "I don't know if it is true or not. I don't think so. I do know football and in football anything can happen. In one or two weeks you can know if it's true or not.

"I don't need to ask the club about it. There is no reason to ask."

Two days later, and a year after winning the Premier League, the Italian was gone.

City said in a statement that "the club has failed to achieve any of its stated targets this year, with the exception of qualification for next season's Uefa Champions League."

Pellegrini would be appointed on a three-year deal the following month.

Martinez was also soon heading for pastures new. Despite failing to keep Wigan in the top-flight – the Latics would finish third bottom, three points from safety – he was named as Everton's new manager.

But his place in Wigan's history had already been secured. "Everyone wrote us off before the game, but we were following a dream," Martinez said after the game at Wembley.

"You cannot describe the feeling at the moment. My players faced adversity and played with a smile. I am so proud of them."