Police said Jacob Helmsley, 24, made offensive gestures to opposing supporters during the Seagulls’ fixture against Crystal Palace on January 14.
He had entered the field of play to celebrate following a goal scored by Brighton and made gestures to incite the Crystal Palace supporters, Sussex Police added.
Police said he then ran back into the stands in a bid to evade being detected. But thanks to excellent CCTV, club staff kept track of him and were able to hand him over to the police for an arrest just minutes later at half time.
While speaking to officers, he said: “Mate, I just ran on the pitch in front of all those people.”
Sussex Police said he claimed he did not realise he would be arrested and interviewed as a result, only learning the seriousness of the offence too late.
Helmsley, of Amaryllis Road, Burgess Hill, was charged with going into the playing area of a football match, contrary to the Football Offences Act.
At Brighton Magistrates’ Court on June 9, he admitted the offence and was ordered to pay a £400 fine, with a £40 victim surcharge and £85 court costs.
Sussex Police’s dedicated football officer PC Darren Balkham said: “In recent months we have seen a concerning rise in the number of incidents of fans going onto the pitch.
“Helmsley claimed he was only celebrating and having fun, but accepted he had caused disruption and apologised. He was seen to antagonise opposing fans at the game.
“Fans who go onto the pitch without authority cause a danger to players, club staff and stewards, other fans, and to themselves.
“This conviction demonstrates that anyone invading the pitch is committing a criminal offence, and we will not tolerate it.
“Working in partnership with Brighton & Hove Albion, we are determined to pursue offenders and prosecute them.
“Helmsley was given a Football Banning Order for three years which prevents him attending all football events within the UK and bars him from travel when the England team are playing outside the UK. He also faces further action from Brighton & Hove Albion.
“This is the price he has to pay for his moment of madness.”
A Brighton & Hove Albion club spokesperson said: "We welcome the verdict and thank Sussex Police and the court for their support in prosecuting the offender.
"There is never an excuse for supporters to leave the stands and to enter the pitch in this way, as puts their own and others safety at risk.
"We saw a worrying trend in pitch incursions at the end of last season across the UK, and all supporters should be reminded this is a criminal offence.
"The safety of players, officials, stewards and staff is of paramount importance, and it is essential they are able to go about their work without the disruption or fear of pitch invasions.
"So, in addition to the punishment handed down by the court, he will also face a significant ban from all home and away Brighton & Hove Albion fixtures."