Arsene Wenger took charge of his 810th Premier League game on Thursday, equalling Sir Alex Ferguson's record.
His Arsenal side made a short trip to visit Crystal Palace and it was a game that they were expected to win with little problem.
That's because going into the match, Palace sat 16th in the league, just one point above the relegation zone.
And the Gunners made a good start to the game, going 1-0 up after 25 minutes thanks to Shkodran Mustafi, who kept his cool to put his side in front from close range.
Wenger's team went into half time ahead, but Palace came out strong in the second and it took Roy Hodgson's men just four minutes to equalise after the break.
Andros Townsend finished well from inside the box after hard work from Wilfred Zaha on the wing.
Although the finish was good, Arsenal's defending has been heavily criticised, and not just for conceding the goal.
In fact, two players in particular, have been singled out by fans for one especially poor moment early in the second half.
ARSENAL'S DEFENSIVE WOES
Hector Bellerin and Granit Xhaka appeared to have Wilfried Zaha and Ruben Loftus-Cheek covered in a 2 v 2 situation on the right wing.
But the pair were cut open by a simple one-two pass between the Palace players, which led to Loftus-Cheek having a clear run into the Arsenal box.
Check it out below.
Unsurprisingly, Gunners fans were quick to voice their opinions on the pair over Twitter, with many suggesting they shouldn't be anywhere near the first team.
Luckily for Xhaka and Bellerin, Alexis Sanchez was able to spare their blushes. He scored two goals in four minutes to restore Arsenal's lead at Selhurst Park.
James Tomkins' late header wasn't enough for Palace as the hosts were beaten 3-2, meaning they're still struggling just above the bottom three.