Ferran Torres scored a second-half penalty to salvage a 1-1 draw for wasteful Barcelona against Napoli in the first leg of their Europa League knockout round play-off.
Barca were competing in Europe's secondary competition for the first time since 2003-04 and enjoyed the better of the game, but Xavi's men could not turn their superiority into a win.
Napoli actually took the lead through Piotr Zielinski, as Barca went close through Torres, Pedri and Pierre-Emerick Aubameyang, who was making his first start since joining from Arsenal.
The hosts were similarly dominant in the second half and got a deserved equaliser from the spot, but Napoli held out for a draw ahead of next week's second leg at Stadio Diego Armando Maradona.
A bright start saw Barca go close several times, with Nico Gonzalez testing Alex Meret and Aubameyang shaving the outside of the post.
Victor Osimhen shot at Marc-Andre ter Stegen from a tight angle soon after on the break, but Barca continued to probe, with Torres spurning a glorious chance when shooting wide with only Meret to beat in the 28th minute.
Napoli capitalised with the next attack, Zielinski smashing at Ter Stegen before burying the rebound to round off an excellent move.
Barca's level dipped initially after the break, but they were quite literally handed a lifeline just before the hour as Adama Traore's cross clipped Juan Jesus' hand, and Torres converted the spot-kick after the VAR's intervention.
Barca piled the pressure on towards the end, but Torres blazed over from 12 yards and Luuk de Jong saw an overhead kick go agonisingly wide.