Lamine Yamal saved a draw for Barcelona with a 96th-minute penalty, denying Newcastle United a famous Champions League victory.
Newcastle appeared to have gained control of the first leg of their last-16 contest when Harvey Barnes scored late on.
But Barcelona was awarded a penalty deep into stoppage time after Malick Thiaw pulled down substitute Dani Olmo inside the box.
Lamine Yamal stepped up, coolly sending goalkeeper Aaron Ramsdale the wrong way to draw the game before the return encounter at the Nou Camp next week.
Newcastle were only seconds away from upsetting the five-time champions when they received a sucker punch.
Even the measured head coach Eddie Howe termed this game the most important in Newcastle’s recent history, and the exuberant hosts definitely regarded it as such when they went head-to-head with Barcelona.
With memories of Newcastle’s stunning victory over Barcelona in 1997 still vivid in these parts, thanks to a hat-trick from the watching Tino Asprilla, Howe’s players appeared determined to achieve a historic result in the first leg.
Barnes duly stepped up with a superb strike from replacement Jacob Murphy’s cross that Barcelona goalkeeper Joan Garcia couldn’t keep out, sending the stadium into a frenzy in the 86th minute.
But there was still time for another late twist, and Lamine Yamal made it 1-1 with the final kick of the game, ensuring Barcelona did not have to overcome a deficit going into the second leg.
Newcastle gave their all in the game. Midway through the second half, Howe made an attacking triple substitution, bringing on Tino Livramento, Murphy, and top scorer Anthony Gordon, who was too ill to start.
The move paid off as Gordon found Murphy, who set up Barnes to open the scoring. Barnes was taken off late, to a standing ovation, but the devastated forward was eventually left with his hands on his head.
After keeping Lamine Yamal quiet in open play all night, Newcastle were left to rue a late sucker punch.
Newcastle faces Chelsea at Stamford Bridge on Saturday, 14 March (17:30 GMT), followed by a return match against Barcelona at the Nou Camp on Wednesday, 18 March (17:45 GMT).
Barcelona hosts Sevilla at the Nou Camp on Sunday, March 15 (15:15 GMT) before the second leg.
