Iran supporters camped outside the Portugal football team's hotel in the Russian city of Saransk making loud noises ahead of their World Cup game.
Dozens of fans turned up on Sunday night with vuvuzelas, bells and drums and to try to keep the team awake.
Portugal star Cristiano Ronaldo was seen asking the fans for quiet, gesturing that he was trying to sleep.
Iran need to beat Portugal in their Monday match to progress to the knockout rounds of the tournament.
Police were first called to the Hotel Mercure at around 23:00 local time, when a first group of Iranian fans arrived at the hotel and began to sing.
Ronaldo's appearance at the hotel window reportedly drove the first group to leave, before a second wave of supporters arrived and continued to make noise through the night.