Barcelona won at the Anoeta for the first time in nearly a decade to take a 1-0 lead after the first leg of the Copa del Rey quarterfinal clash with Real Sociedad.
Neymar won a penalty and then got up to convert it to give the Catalans a first win in San Sebastian since a 2-0 La Liga success in May 2007.
It was only the Brazilian's eighth goal of the season but it helped strengthen Barcelona's grip on the trophy they have won each of the past two years ahead of the return leg at the Nou Camp in a week's time.
Sociedad made a bright start, pressing Barcelona high up the pitch to make things difficult for Luis Enrique's team.
It almost brought an early goal, forcing Samuel Umtiti into two quick mistakes -- the second of which allowed Mikel Oyarzabal to advance towards goal before sending a shot just over the crossbar.
It was somewhat against the run of play when Barcelona scored. This time the hosts were caught out in defence and Neymar drew a foul from right-back Aritz Elustondo before regaining his feet to slam the resulting spot-kick beyond Geronimo Rulli, placing the ball right inside the left-hand post giving the goalkeeper no chance.
It had looked set to be an enthralling first half after a bright opening but things were rather muted thereafter, as Barcelona sat back with their advantage.
Sociedad twice went close before half-time but Asier Illarramendi's deflected shot flew narrowly wide as did Raul Navas' towering header.
The visitors nearly extended their lead as the hour mark approached with a lovely flowing attack as Luis Suarez and Lionel Messi flicked the ball between themselves before setting up Neymar, whose shot just missed the bottom corner of the net.
Navas' awful back pass then almost resulted in an own goal but Rulli managed to scramble back and concede a corner.
A rare Sociedad attack saw them come close to an equalising goal after 63 minutes. David Zurutuza charged forward and sent Yuri free down the left side of the penalty area but the left-back's cross-shot whizzed agonisingly past the bottom-far corner.
Late action saw a Messi free kick skim the top of the net before Navas kept his side in the tie with a brave block to keep out a powerful shot from Andre Gomes, with the ball striking the defender flush in the face.