Joao Felix scored the only goal of the game as Barcelona won 1-0 at Atletico Madrid on Sunday night.
The Portugal forward is on loan at Barca from Atletico and his deal does not include an option to make the move permanent at the end of the season.
Therefore, Felix is expected to return to Atletico next summer as he is under contract with the capital club until June 2029.
Many players choose not to celebrate when they score against their former clubs, or indeed clubs to which they still belong.
But Felix was not shy as he celebrated after beating Atletico keeper Jan Oblak with a fine chipped finish in the 28th minute on Sunday.
The 24-year-old leapt onto an advertising board beyond Oblak's goal and triumphantly raised both arms above his head.
When asked after Sunday's game about his decision to celebrate, Felix told reporters: "People have been talking about me all week, but I don't pay attention to that.
"I'm just doing my job. I don't care what people say. I work every day to become better.
"The celebration was spontaneous. It was a release of what I had been through last summer. It was for my family."
Felix has now scored five goals in 17 appearances for Barcelona this season.
He has netted 34 times in 131 games for Atletico since signing from Benfica for a transfer fee in excess of £100 million in July 2019.
Highlights: Barcelona 1-0 Atletico Madrid
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