Leeds United supporters jeered en masse as three Manchester City players observed the Islamic holy month of Ramadan.
Referee Peter Bankes called a stoppage in play in the 12th minute, allowing Rayan Ait-Nouri, Rayan Cherki and Omar Marmoush to break their fast at the time of sunset.
The trio could take on food and water on the touchline, with both teams heading over to their respective benches for around a minute.
That was met by a chorus of persistent boos and offensive chanting from home fans until the match restarted.
A message relaying that players were breaking fast was beamed onto Elland Road's screens at the same time as the dissent.
City requested the introduction of a break on Friday, which Leeds accommodated and confirmed 24 hours ahead of the meeting.
Daniel Farke's starting XI did not include any Muslim players.
Ramadan will end next month, with a break in fasting expected during the FA Cup clash between Wrexham and Chelsea in next week's 5:45pm kick off.
City travel to Newcastle United in the 8pm slot that day and their Muslim stars, including Abdukodir Khusanov, will have been able to take on food and water beforehand.
'They follow this religious tradition,' Guardiola said on the eve of the Leeds trip. 'We have good nutritionists and they adapt to what the team needs.
'We cannot adapt the schedule for the Premier League [kick-off] times and I think they are used to it - they are not young and have been playing [for] many years during this period.
'For the players I think it is not new. Both Rayans, Omar and Khusa, it is not the first time for [observing] Ramadan and they know perfectly how to handle it.'
The Premier League confirmed earlier month that Ramadan breaks would be used in matches again this season to allow players to break their fast during the holy month, which runs from February 17 to March 19.
Given sunset in the UK ranges from around 5PM to 6.30PM at this time of the year, the only games that are affected are 5:30PM kick-offs on a Saturday and the 4:30PM kick-off on a Sunday.
The protocol for these breaks sees teams and match officials discuss beforehand whether a pause is required, before they settle on an approximate time when the stoppage will take place.
It was in 2021 when Ramadan breaks were introduced, with Leicester City's clash against Crystal Palace in April of that year being the first occasion they were seen.
On that occasion, the match was paused at a goal-kick around 30 minutes into the game to allow Leicester's Wesley Fofana and Palace's Cheikhou Kouyate to take on board liquids and energy gels.
Speaking on BBC Five Live, former England goalkeeper Paul Robinson highlighted the importance of the breaks.
He said: 'I think it's very good for the players. We talk about the athletes and how fine-tuned they are at the moment.
'To go that long without food and drink, it is vitally important that they have that break.'
Other Muslim names in the Premier League include Mohamed Salah, William Saliba, and Amad Diallo, while City legends Ilkay Gundogan, Riyad Mahrez and Yaya Toure are also followers of Islam.
Speaking back in 2023, former Everton and Watford Abdoulaye Doucoure hailed the top flight for its work in making Muslim players feel welcome.
'In the Premier League you are free to do whatever suits you. They will never do anything against your faith and this is great,' he told BBC Sport.
'I fast every day, I don't miss any day. It has become normal and very easy for me. Training is still the same during Ramadan but when we go [for away matches], we might need to eat later than the others so the chef prepares food for us, making sure everything is in place as at home. We get halal food so there are no problems,'
In 2022, former Liverpool player Sadio Mane also revealed the club altered their training schedules to support their Muslim players during the month of Ramadan.