Barcelona extended their lead at the top of La Liga on Friday as they overcame stiff resistance from Espanyol to win the Catalan derby 1-0 at the Camp Nou.
Barça now lead second-placed Atletico Madrid by four points and Real Madrid by nine with both sides from the capital having played a game less.
Kiko Casilla was forced into an early save from Sanchez after nice work by Iniesta and Lionel Messi.
But it was the visitors who had the best chance of the half when Victor Sanchez sneaked in behind Dani Alves and Victor Valdes had to race from his line to turn the midfielder's effort behind.
Barça came to life just before the break as Iniesta's volley from the edge of the area was parried by Casilla before Alves struck the post from similar range.
The pattern continued after the restart with Espanyol happy to sit ten men behind the ball and wait for Barça. Gerardo Martino's men nearly made the breakthrough on 54 minutes when Casilla produced a fine save to turn away Messi's flicked header.
Neymar then bent a stunning effort inches wide of Casilla's left-hand post as the pressure built from Barça.
And it was the Brazilian who finally unlocked the Espanyol defence as his wonderful low cross between the legs of two defenders left Sanchez with the simplest of finishes at the back post to register his seventh goal of the season.
Messi saw a free-kick fly just wide with nine minutes remaining as Barça went in search of the goal that would finish the game off.
Substitute Pedro Rodriguez ought to have doubled the advantage when he fired into Casilla's legs two minutes from time, but Barca held on to register their tenth clean sheet in 17 games this season.