Lionel Messi missed a penalty kick but rebounded by scoring his record 350th goal in the Spanish league in Barcelona's 2-0 win at Alaves on Saturday.
Messi also scored the second in leading the club to its second consecutive victory to start the league.
Barcelona was still without Ousmane Dembele, who was announced as Neymar's replacement on Friday, and it also couldn't count on the injured Luis Suarez.
With Messi as its lone star, Barcelona struggled in the beginning at Mendizorroza Stadium, but it gradually took control and cruised to victory following Messi's pair of second-half goals.
"We overcame a tough test," Barcelona coach Ernesto Valverde said. "It was difficult to get the first goal, we had to be patient."
Messi missed the penalty when his mid-height shot into the left corner was saved by the fingertips of Alaves goalkeeper Fernando Pacheco.
Alaves, who surprised last season as a promoted club by finishing ninth in the league and reaching the Copa del Rey final against Barcelona, opened with a 1-0 loss at Leganes.
Brazil midfielder Paulinho, signed by Barcelona for 40 million euros ($47.2 million) in the offseason, came into the match as a substitute late in the second half to make his official club debut.
Messi scored the milestone goal in La Liga more than 12 years after his first, when he was only 17.
He has 66 more than Real Madrid's Cristiano Ronaldo, his closest challenger in the all-time list.
Messi is only the second player to have surpassed 350 goals in the top five European leagues, after Bayern Munich's Gerd Mueller, who ended his career with 365 in the Bundesliga.
Messi has at least one Spanish league goal in 14 straight seasons.
He opened the scoring in the second half after receiving a pass from Jordi Alba inside the area and firing a left-footed shot into the corner. The second came after a blunder by the Alaves defense about 10 minutes later.
Messi later also hit the crossbar from just inside the area. He hit the woodwork three times in Barcelona's opening win over Real Betis last week, but he was yet to score in the league this season.
Defending champion Real Madrid, which also won its opener, hosts Valencia on Sunday.
Two goals in the first five minutes put Atletico Madrid on track for a comfortable 5-1 win at Las Palmas. It was the first league win for Atletico, which opened with a 2-2 draw at promoted Girona.
It was the second consecutive loss for Las Palmas.
Ten-man Levante rallied from two goals down to earn a 2-2 home draw against Deportivo La Coruna.
Deportivo was ahead 2-0 after the first half hour, but Levante pulled closer before halftime and equalized following a controversial penalty kick call in the 83rd at Ciutat de Valencia Stadium.
Ivan "Ivi" Lopez converted the penalty to keep the hosts unbeaten.
Midfielder Jose Luis Morales was sent off with a second yellow card in the 76th.
Girona beat Malaga 1-0 for its first win in the Spanish league. Girona was on its way to victory in its opener against Atletico Madrid but relinquished a 2-0 lead despite playing with an extra man.