England players were shocked by jeering at the gesture from a minority of fans in two friendlies prior to the tournament. Manager Gareth Southgate, Prime Minister Boris Johnson and leading football figures had appealed for a stop to that.
Once again, there was some jeering from a small section as players briefly went down on one knee, but many others among the 25,000 crowd in a sun-kissed Wembley began applauding and cheering.
The gesture, borrowed from American NFL quarterback Colin Kaepernick and popularised by the Black Lives Matter movement last year, has generated off-field controversy around Europe in the build-up to the 24-nation Euros.
Critics view it as an unwanted politicization of sport and expression of sympathy with far-left politics.
But England players and other national teams also taking the knee say it is simply a show of solidarity against racial discrimination still prevalent in football and around the world.