Adrian Cieslewicz cancelled out Jake Forster-Caskey's goal to earn non-league Wrexham a deserved third-round replay against Brighton.
Cieslewicz levelled on 62 minutes when his deflected shot looped over keeper Peter Brezovan.
Forster-Caskey's tap in, his second goal in as many games, had given Brighton a second-half lead.
The 17-year-old netted from close range from Kazenga LuaLua's cross before Cieslewicz took the tie back to Wales.
The sides will replay at the Racecourse on 17 January, with Wrexham attempting to reach the fourth round for the first time since 2000.
Albion made six changes to the side that had beaten Championship leaders Southampton in their previous game, with Ben Sampayo handed a full debut and Grant Hall making his first start.
In contrast, player-manager Andy Morrell was the only change to Wrexham's side, with Mathias Pogba ruled out through injury.
And a mistake by visiting keeper Joslain Mayebi handed Brighton an early opportunity to assert their superiority - but LuaLua could only direct his shot across the face of goal.
However, having survived the early scare, Wrexham settled into the game, with Jake Speight's pace in particular causing problems for Seagulls captain Inigo Calderon.
Mayebi was called into action on 13 minutes when he did well to save Forster-Caskey's shot, while Will Buckley also had a shot blocked.
Both sides were playing an open, expansive game and only a last-ditch tackle from Matt Sparrow denied Speight following Morrell's cross.
A long-range effort by LuaLua flew past the post for the hosts before the lively Speight twice went close at the other end, with Jamie Tolley also putting a shot wide and forcing Brezovan into saving his 20-yard effort.
But having held out for 45 minutes, Wrexham conceded only 90 seconds into the second half with Forster-Caskey tapping in LuaLua's precise cross from the byline.
Having provided the assist for the goal, LuaLua was forced off the field five minutes later with a hamstring injury and was replaced by Torbjorn Agdestein.
Forster-Caskey came close to a second with a ferocious, swerving shot that Mayebi did well to hold on to but Wrexham refused to buckle and they were level on 62 minutes.
Cieslewicz cut inside two defenders before his shot from inside the penalty area took a deflection and looped over goalkeeper Brezovan.
Brighton manager Gus Poyet's response was to make two further changes with the introduction of debutants Yaser Kasim and Anton Rodgers, son of Swansea boss Brendan.
Rodgers and fellow substitute Agdestein had chances to restore Brighton's lead but it would have been harsh on a Wrexham side who had shown plenty of endeavour.
Indeed, the visitors could have snatched a dramatic victory in stoppage time when Tolley saw his fierce drive saved by Brezovan.
And Wrexham's players were applauded off the field at the end of the game by more than 2,000 of their travelling fans.
Brighton manager Gus Poyet told BBC Sussex: "We learnt a lot from plenty of players, especially the young ones.
"We were in control in the last 20 minutes and it was a beautiful team to see play.
"We have another opportunity next week for the kids to play an important game. There's a chance the whole second team will play."