Neymar came on as a substitute to score twice from passes by Lionel Messi as Barcelona beat Athletic Bilbao 2-0 and maintained its lead of the Spanish league on Saturday.
Neymar again started on Barcelona's bench and had to watch Munir El Haddadi create Barcelona's best chances until he replaced the young forward in the 62nd minute.
But Messi soon played Neymar clear for the Brazil striker to score his first goal for Barcelona this season in the 79th.
Five minutes later, Messi dribbled to the end line before passing back for Neymar to slot in his second and make Barcelona the only team to have won all three games this season.
"Messi is not only the best in the world for the goals he scores but also because of the assists he makes," said Barcelona coach Luis Enrique. "He is the best in every facet of the attack. I watch him in practice and he does things that you can't even see on a PlayStation."
Title rivals Real Madrid and Atletico Madrid meet later in a rematch of last season's Champions League final, when Madrid beat Spanish champion Atletico 4-1 in added time.
Barcelona opens its Champions League campaign at home against APOEL on Wednesday, when Bilbao hosts Shakhtar Donetsk.
Barcelona dominated Bilbao, which finished fourth in La Liga last season, at Camp Nou with Munir and Pedro Rodriguez leading its onslaught of shots that goalkeeper Gorka Iraizoz did well to turn back.
It wasn't until Neymar's entry that the hosts finally broke through.
While Neymar went a long way to convincing Enrique he should regain his starting role, Messi continued his impressive start. Of Barcelona's six goals through three wins, the Argentina forward has scored two and set up three more.
Midfielder Sergio Busquets cued Barcelona's opener when he stole the ball and passed for Messi, who quickly sent the ball forward to Neymar on the break.
Messi did most of the work on the second goal, turning the defense on its heels before finding Neymar alone in the middle of the area to drive the ball inside the post.
Barcelona defender Javier Mascherano was substituted for Gerard Pique at halftime after he received a kick to the head from Aritz Aduriz while disputing a high ball.
Also later, Malaga hosted Levante while Real Sociedad visited Celta Vigo.