The Brazilian defender ran across the pitch to console his international team-mate after he blazed his spot-kick over the bar.
The episode had already become one of the images of the final in Budapest — a gesture of human solidarity in the most pressurised setting in club football. Marquinhos spoke about what happened, and what followed, at a pre-World Cup press conference for the Brazil squad.
"A day later, I received a message from him thanking me for that moment, for the support, for the hug, and for the words I'd shared with him. I told him it had been my greatest victory that night, and that the reaction it generated was great. My mum came over, proud of what I'd done, along with my wife, family and brothers. It was the best accolade I received that night."
He described the thought process that led to the embrace, drawing on his own painful experience of missing a penalty for PSG against Real Madrid in the 2022 Champions League.
"I was ready and prepared to celebrate. But when I started running, I saw him right in front of me and my team going past him — the same image as after my penalty in 2022. That's when I started thinking about my team-mate, having empathy, because I've been through a moment like that and I know the responsibility."
He revealed the exact words he said to Gabriel in those seconds.
"I told him to stay strong, to hold his head high because he'd had an incredible season and an incredible match. I told him that, in my opinion, he was the best centre-back in the world this season. He simply didn't deserve to carry that burden. I told him that nothing about that moment would take away from the wonderful season he'd had and that we were going to need him very much."
Marquinhos has captained PSG to back-to-back Champions League titles and is preparing for what may be his final World Cup as a Brazil player at 31.