The Brazilian extended his lead at the top of the scoring charts by scoring two at Camp Nou, with Luis Suarez and Lionel Messi also on the scoresheet in a comfortable victory
David Moyes recorded a memorable 1-0 win over the champions last season but his successor as head coach, Eusebio Sacristan, a former Barca midfielder, endured an unhappy return to Camp Nou against the leaders.
Neymar finished a fine team move to open the scoring on 22 minutes before another superb Luis Suarez volley made it 2-0 just before half-time, just as Sociedad had begun to threaten.
Barca made it three with Neymar’s second early in the second half as the Catalans moved into cruise control and Lionel Messi grabbed a late fourth, with Claudio Bravo largely a spectator throughout the 90 minutes.
The victory puts more pressure on Real Madrid, with Rafael Benitez’s side now nine points behind Barca ahead of their trip to Eibar on Sunday, while Sociedad remain just two points outside the bottom three.
Geronimo Rulli raced out sharply to block Suarez’s run after Neymar’s fine through-ball as Barca began firmly on the front foot.
Rulli then snatched the ball superbly from the feet of Neymar as he raced onto Messi’s pass before Andres Iniesta headed against the base of the post from 12 yards just two minutes later following a fine Suarez cross.
Sergio Canales blazed a half-volley high and wide from 25 yards out on a rare Sociedad attack but Barca broke the deadlock with 22 minutes played – and in some style.
Messi controlled and flicked the ball into Dani Alves’ path brilliantly, and the full-back’s low cross was met by Neymar, who fired first time into the top corner as he raced into the penalty area.
Sociedad grew into the half but were unable to create any chances for a leveller, and Suarez made it 2-0 just before the break as he met another Alves cross with a stunning volley which flew into the bottom corner from 12 yards out.
And the game was ended as a contest just seven minutes after the break. Jeremy Mathieu raced in behind down the left following Iniesta’s pass and squared the ball for Neymar, who was left with a simple finish from close range.
Messi, making his 600th career appearance, volleyed just wide of the near post after being teed up by Neymar, and Rulli clutched the ball gratefully to his chest after the Argentina star shot straight down the middle after combining with Neymar again a minute later.
Sociedad pushed for a way back into the match as Barca took their foot off the gas, though full-back Yuri lashed into the side-netting when presented with their best opening to the left of the penalty area.
Substitute Bruma caused some problems as a late substitute, firing just wide from 18 yards before cutting inside Gerard Pique and forcing Bravo into a brilliant point-blank stop, but Messi came close a minute later as he curled a shot onto the crossbar from just inside the box.
Messi did add a fourth in stoppage time as all three of Barca’s devastating attack combined. Neymar skipped inside from the right and played a one-two with Suarez before squaring the ball to an unmarked Messi at the far post, and he tapped home.