Ghanaian forward Inaki Williams left the San Mames Stadium half-naked after a La Liga match when he gave away his jersey and shorts to Athletic Club fans.
The 29-year-old scored as a 10-man Bilbao team drew with local rivals Getafe.
Williams, a fan favorite and an icon of the Spanish city, showed his appreciation to some of the fans by gifting his jersey, the inner shirt he wore, and his shorts to young supporters who eagerly sought a memento with him.
The generous act left Williams nearly half-naked as he walked into the tunnel wearing only his underpants.
The Basque-born player put smiles on the faces of the fans by also taking photos and signing autographs.
The forward scored one of the goals in Athletic Club's 2-2 game against Getafe in mid-week.