Stacey Andrew, aged 27, from Boston in Lincolnshire, was at the Sheffield venue on Monday when she was hit by a flare.
She told the BBC: "The flare hit my head and fell down my top, at first I didn't realise what had happened until people shouted.
"It looks like someone let a firework off on my chest."
Former Oasis frontman Liam has now reached out to her on Twitter and condemned epople for letting off flares.
He said: “I’m sorry to hear what happened to Stacey Andrew in Sheffield the other night.
“It’s not cool, people need to chill the f**k out with the flares.
“Can someone from her family get in contact with us.”
Ms Andrew said it was her first gig.
She and her partner Callum Mutton were near the front and the people with flares were just behind them.
She said: “I didn't realise what had happened then people started patting me. My shirt was in flames and a man ripped it off.
"People were shouting, 'She's on fire'."
In a statement, Fly DSA Arena spokesman Dominic Stokes: “The irresponsible behaviour of the concert goer who threw the flare along with any other people within their party who were aware of the possibility of their actions cannot be condoned and they should be held accountable for their actions."
He said Ms Andrew and Mr Mutton were both seen at the venue by an on-duty paramedic and advised to go to hospital.
The Arena said it had contacted them through social media to speak with them directly.
Arena staff offered a taxi but in the end Mr Mutton drove to hospital.
South Yorkshire Police is investigating the incident.