Arsenal's Premier League title challenge was dealt another seismic blow as Joao Pedro's penalty secured a 1-1 draw for Brighton on Saturday to leave the Gunners five points adrift of leaders Liverpool, who have two games in hand.
Mikel Arteta's attacking options were limited by illness and injury but 17-year-old Ethan Nwaneri took his chance to shine with a composed finish to put the visitors in front.
However, Arsenal saw two vital points slip away when William Saliba was harshly punished for a clash of heads with Joao Pedro and the Brazilian slotted home the resulting spot-kick.
Liverpool can now further extend their lead at the top and close in on a record-equalling 20th English top-flight title when they host struggling Manchester United on Sunday.
Already shorn of talisman Bukayo Saka for the next two months with a hamstring injury, Arsenal's attacking options were further depleted by illness.
Kai Havertz failed to even make the matchday squad for the second consecutive game, while captain Martin Odegaard and Gabriel Martinelli were only fit enough for appearances as second-half substitutes.
Nwaneri was the beneficiary with a second consecutive start and showed why he is one of the Premier League's rising stars with a clinical finish for the opening goal.
The teenager still had plenty to do as he raced onto Mikel Merino's ball over the top but his pace took him beyond the Brighton defence before firing low into the far corner on 16 minutes.
Arsenal went on to control the remainder of the first half but lacked any penetration without their quartet of attacking stars to build on their lead.
Merino had the one big opportunity to double the Gunners' advantage early in the second period when he skewed wide from Declan Rice's free-kick.
Moments later the visitors were rocked by a controversial call that could have huge ramifications for the title race.
There was the slightest touch from Saliba's head onto Joao Pedro's but the Brighton forward went down clutching his face and got the reward of a spot-kick.
The Seagulls captain for the day, in the absence of Lewis Dunk, confidently stroked home the penalty to level.
Arteta responded immediately by summoning Odegaard from the bench, while Martinelli had replaced Nwaneri at the break.
However, it was Brighton who looked the most likely winners in the closing stages.
Yakuba Minteh wasted a great chance to end their now eight-game winless run when his shot across goal evaded both Yasin Ayari and Kaoru Mitoma and slid wide of the far post.
But a point is enough to edge Brighton back into 10th.