Barcelona started life without Lionel Messi by defeating Real Sociedad 4-2 in their La Liga opener at the Camp Nou on Sunday even if fans admitted it felt like "a leap into the unknown".

Captain Gerard Pique gave them a 19th minute lead with his 50th goal for the club.

Martin Braithwaite found the net in first half injury time and in the 59th minute. Sergi Roberto added a fourth in the last minute of the game.

Just over 20,000 fans were in attendance as crowds returned for the first time since the pandemic.

However, they had to hold their breath at one stage when Sociedad came back from 3-0 down to get to 3-2 thanks to goals from 20-year-old Julen Lobete in the 82nd minute and a 30-metre free-kick from skipper Mikel Oyarzabal three minutes later.

Six-time Ballon d'Or winner Messi called time on his two-decade career at Barcelona last week and moved to Paris Saint-Germain.

Messi's memory lingered heavy over the Camp Nou on Sunday despite the removal of a giant photograph of the Argentine superstar from the entrance in the wake of his move to France. 

Some banners were in place well before kick-off venting the fans anger towards president Joan Laporta. One read "Laporta, Barca is not your business", while another proclaimed "Barca yes, Laporta no!"

"It was a big emotional blow," said 23-year-old Barca fan Adria De Lucas. "I was in my room when I saw the news. I started sending messages to all my friends, and no one believed it. It was emotionally hard."

The supporter added: "It's a leap into the unknown (without Messi). We will see what happens."

Inside the Camp Nou, fans made the most of their return after 18 months, chanting "Messi! Messi!". Banners expressed their "eternal gratitude".

"The supporters are with us, they want to see football," said Pique. "We knew they were going to react that way. We all know what Leo represents, but everything changes and we have to keep going.

"We will be very competitive and we will fight for titles to the end. We will not have his talent, but we have proven that we can all play together."