Poland captain Robert Lewandowski risked the wrath of his own fans as he pointed to the "Respect" symbol on his shirt during a chorus of boos sent England's way as they took the knee before kick-off at Warsaw's Stadion Narodowy.
Poland fans applauded England's national anthem, but minutes later, the situation changed with boos reverbrating around the stadium as The Three Lions took the knee. As that scenario unfolded on the pitch, cameras panned towards Lewandowski, who appeared to hit back at the Polish fans.
The Bayern Munich striker pointed to the word "Respect" on his shirt sleeve as the booing intensified. Prior to England's Euro 2020 campaign, Southgate spoke about the issue after his side were booed by their own fans during a warm-up game against Austria.
"We are collectively really disappointed that it happened," the England boss said at the time. "You have to put yourself in the shoes of an England player about to represent his country and because we are all trying to support the move for equality, the move for supporting our team-mates… some of the experiences they have been through in their lives.
"Some people decide to boo. I think those people should put themselves in the shoes of those young players and how that must feel. If that was their children, if they are old enough to have children, how would they feel about their kids being in that sort of situation.
"Most important thing for our players is to know we are totally united on it, we are totally committed to supporting each other, supporting the team. We feel more than ever determined to take the knee through this tournament.
"We accept that there might be an adverse reaction and we are just going to ignore that and move forward. The players are sick of talking about the consequences of should they, shouldn't they. They have had enough really."