Wigan Athletic have promised a full investigation into the pitch invasion that marred their FA Cup win over Manchester City on Monday.
Will Grigg scored the only goal of the game after 79 minutes to book a quarter-final tie against Southampton for Paul Cook's side and end the runaway Premier League leaders' prospects of a quadruple.
Hundreds of fans streamed onto the pitch in celebration after the final whistle, with City striker Sergio Aguero involved in an altercation with one individual who approached the player from behind.
Wigan accept that "a minority" of fans "acted in an inappropriate manner" and have vowed to take action.
A statement released by the League One club on Tuesday read: "Following Monday night's enthralling victory over Manchester City in the Emirates FA Cup, the club were disappointed to see supporters encroach the pitch at the final whistle.
"Chief Executive Jonathan Jackson commented: 'Whilst we appreciate that the vast majority of supporters who ran on to the pitch did so spontaneously to celebrate a famous victory, we were disappointed with the action of a minority of supporters who acted in an inappropriate manner.
"'Player and staff safety is of paramount importance and we will conduct a full investigation.
"'However, it is important to not let the actions of a few supporters detract from an incredible night at the DW Stadium. A special atmosphere was created by both sets of supporters and the match was yet another memorable day in the history of Wigan Athletic.'"
The FA is expected to conduct their own investigation into the incident involving Aguero, who was seen lashing out at the fan as Wigan defender Chey Dunkley tried to calm the situation.
Meanwhile, some of the travelling City supporters had an altercation with stewards, during which objects – including an advertising hoarding – were thrown.
Reacting to the events, Wigan chairman David Sharpe told BBC Radio 5 Live: "It is not nice to see, football is emotional, it is what it does to fans. But I don't like to see this at the end of the game.
"It is a massive result, but we have to stay classy in football. I don't like what I am seeing here."
|Dodgers top Mets in Kershaw´s return from DL|
|MLS Review: Red Bulls end Dallas´ unbeaten run, Sporting stage comeback|
|Hierro: This Spain team similar to 2010 World Cup champions|
|Dowrich, Holder lead Windies fightback after poor start|
|With Neymar back, Brazil are World Cup favourites – Lugano|
|Alba: I don´t understand the criticism of Messi|
|He has sacrificed a lot – Stuani praises Suarez|
|Manning says Brees deserves to break his record for career passing yards|
|Hornets want Walker to play entire career with Charlotte|
|Avalanche sign Grubauer to three-year extension|
|Argentina struggles down to team, not just Messi – Hierro|
|Casey leads Travelers by four after firing 62|
|Scotland run riot in Argentina as Hourcade tenure ends in defeat|
|Germany´s Rudy in doubt for South Korea clash|
|England produce storming fightback to beat New Zealand|
|Shaqiri, Xhaka facing disciplinary action over goal celebration|
|Kvitova takes WTA lead for wins by easing into Birmingham final|
|Jones: England back on road to being world´s best|
|Germany survive in Sochi but questions remain|
|Germany 2 Sweden 1: Late Kroos winner brings Low´s men back from the brink|
|Perisic dreaming of matching Croatia´s France 98 heroes|
|Veron questions Sampaoli for leaving Icardi out|
|Southgate won´t blame injured Alli for playing through pain barrier|
|Travelers Championship: Course invader drives Rory McIlroy and crowd nuts|
|Saul tells Atletico to renew Oblak deal after Griezmann´s new contract|
|Course invader sends McIlroy & crowd nuts at Travelers Championship|
|Saudi Arabia v Egypt: El Hadary eyes history in dead rubber|
|Referee declines Cheika invite after Australia´s series loss to Ireland|
|Griezmann, Mbappe can eclipse Henry, claims Trezeguet|
|Nawalka hopeful of Glik return against Colombia|
|Mexico outsmart South Korea to join Croatia as unheralded World Cup threats|
|´No drama´ for Southgate after England team sheet leak|
|Hend caught by five in Pulheim as Bjerregaard goes low|
|´Little Pea´ Hernandez hits big Mexico milestone in World Cup win|
|Modric and Rakitic the best midfield in Russia - Corluka|
|Cipriani and Farrell ease pressure on Jones as England avoid SA whitewash|
|South Korea 1 Mexico 2: Hernandez nets landmark goal as last 16 beckons|
|Ozil and Khedira axed by Germany|
|Djokovic plans to use two rackets against Cilic after reaching Queen´s final|
|World Cup of penalties? Russia surpasses Brazil after VAR introduction|
|Neymar ´fully recovered´ but Brazil coach Tite has thigh injury|
|Hansen claims France ´clutching at straws´ after another referee controversy|
|Douglas Costa, Danilo out of Brazil´s Serbia clash|
|Hamilton claims 75th pole as Mercedes dominate in France|
|´Mentally strong´ Salah will overcome World Cup disappointment, says Mane|
|Pekerman contemplating unleashing James and Quintero together|
|Schmidt hopes Australia furnace will produce Ireland diamonds|
|I´m missing practice, but it´s OK - Federer ready for Coric|
|Spain v Morocco: Alba makes case for the defence|
|Team-man Lukaku firmly in the race for individual prize|
|Belgium 5 Tunisia 2: Lukaku and Hazard shine as Red Devils run riot|
|Leaked England team gives Panama no advantage, insists Gomez|
|Mane and Senegal holding no fear for Japan|
|Murray to meet Wawrinka at Eastbourne|
|Nigeria goalkeeper Ikeme in remission after year-long cancer battle|
|Lukaku breaks Belgium record against Tunisia|
|Iran v Portugal: Team Melli bullish over qualification chances|
|Mauresmo to be France´s first female Davis Cup captain|
|Maradona angry at Argentina World Cup performances|
|Ireland cap stunning season with series win over Wallabies|
|Uruguay v Russia: Selection posers for already-qualified pair|
|Federer scraps his way to yet another Halle final|
|Lunin rejected ´3,000 offers´ to join Real Madrid|
|On your bike! Iceland physio sent home after cycling accident|
|Not just Real Madrid interested in Fekir, says Aulas|
|France frustrated by officials again as All Blacks complete sweep in style|
|Jose Enrique reveals brain tumour surgery|
|The referee was a disaster, fumes Matic|
|Lakmal to captain Sri Lanka in Chandimal´s absence|
|Alli back in England training|