Portugal's Euro 2024 Group F win against Turkey in Dortmund on Saturday was halted four times by supporters running onto the pitch for selfies with Cristiano Ronaldo, with two more doing the same postmatch.
Portugal coach Roberto Martinez spoke in grave terms about the incidents after the game saying it should not be allowed to happen and urged other supporters not to follow suit.
"It is a concern, but today we were lucky as intention of the fans were good," he said. "The fans recognise big stars and icons but there is a very difficult situation if their intensions are wrong and players are exposed.
"It shouldn't happen. There is lots of security, so it shouldn't happen. Maybe there is a message to that fans, that this is not the right way [to behave]. The message is that it could get worse for the future and it's not good that the players are so exposed on the pitch."
Ronaldo, now playing his club football in Saudi Arabia with Al Nassr, smiled and posed for a picture with a young boy who evaded security to run onto the playing surface in the 70th minute.
The child, aged around 10 years old, was hugged by Ronaldo before running away from security stewards until he was unable to escape on the side of the pitch.
When he was being led away, stewards and substitutes on the touchline patted the boy on the head, and the crowd inside the stadium cheered as he waved while being led away.
A teenage boy then attempted to repeat the stunt 15 minutes later, but Portugal captain Ronaldo threw his arms in the air and waved him away before security stopped the youngster from reaching the former Real Madrid and Manchester United player.
On both occasions, German referee Felix Zwayer was forced to delay the game until the youngsters were removed from the pitch.
Two more supporters, this time adult males, ran onto the pitch in stoppage time and headed toward Ronaldo with their phones before being stopped by security.
Finally, two more supporters repeated the trick once the final whistle had been blown, not interrupting the game but getting on the pitch nonetheless.
The incidents will trigger an automatic disciplinary investigation by UEFA over security inside the stadium, which is likely to host Germany's round-of-16 fixture and also a semifinal later in the tournament.