The teenage midfielder - who can also play in defence - entered the field in the 92nd minute when he was subbed on for Jurrien Timber. However, Lewis-Skelly had already entered the referee's notebook just over 25 minutes earlier.
Lewis-Skelly was shown a yellow card by Michael Oliver for alleged misconduct on the touchline as tempers flared after City players took offence at what they perceived to be time-wasting by Gunners goalkeeper David Raya.
Islington-born Lewis-Skelly touched the ball only twice during his brief cameo - once to complete a simple pass and then again to complete a clearance.
But he found himself in the thick of the action again after the two sets of players clashed on the field following a late City equaliser scored by John Stones.
After seeing City striker Erling Haaland and Gabriel face off, Lewis-Skelly attempted to intervene and back up his team-mate.
Haaland reacted to Lewis-Skelly's arrival on the scene by dismissively gesturing for him to go away.
After seeing footage of this brief interaction, multiple fans on social media were convinced that Haaland also said to Lewis-Skelly: 'Who the f*** are you?'
Including Lewis-Skelly, eight players were carded during Sunday's game.
Arsenal star Leandro Trossard was sent off just before half-time after committing two bookable offences.
Arsenal were leading 2-1 when Trossard went off.
Lewis-Skelly confronted City star Erling Haaland (second right), who responded dismissively
Riccardo Calafiori hit back with a spectacular solo strike before fellow defender Gabriel headed home from a corner kick to complete the turnaround.
Despite playing the entire second half with a numerical disadvantage, Arsenal held their 2-1 lead until deep into added time when Stones bundled home what could prove to be a crucial goal in this season's title race.