Arsenal's top-four hopes took a significant dent in a 3-0 defeat by Crystal Palace that leaves Tottenham in fourth place after the Premier League weekend
The Gunners do have a game in hand on their north London rivals but this was an out-of-character performance from Mikel Arteta's side, as first-half goals from Jean-Philippe Mateta and Jordan Ayew and a second-half Wilfried Zaha penalty handed fantastic Palace just their second win over Arsenal at Selhurst Park since 1980
The rearranged postponed derby between Spurs and Arsenal, , is shaping up to be a potentially-decisive encounter in the race for Champions League qualification
Crystal Palace have now lost just one of their last 11 games in all competitions as former Gunners legend Patrick Vieira continues to do a fine job
Arteta, , was asked post-match if perhaps one of the reasons for the defeat was the pressure being applied to them by Tottenham in the top-four race
He replied: "No, the pressure has been there the last seven or eight weeks
 Today we didn't perform it's as simple as that
 We were second best in every department it's as simple as that
 We have a game in hand still
 In the nine games a lot will happen
 We have to focus on ourselves
"Buoyed by three of their players - Conor Gallagher, Tyrick Mitchell and Marc Guehi - winning caps for England over the international break, Palace were aggressive from the first whistle
 That desire to win the second balls forced the opening goal when Mateta headed home from close range after Joachim Andersen forced the ball across goal without knowing too much about it
Palace are yet to be beaten when scoring the first goal in the Premier League and only Wolves have taken fewer points than Arsenal from losing positions, so it was not overly surprising to see Palace double their lead before the break
 Ayew galloped onto a crisp pass from Andersen that split Gabriel and Nuno Tavares and slotted home for just his second goal in his last 55 Premier League appearances
Arsenal have not come back from a two-goal deficit at half-time to win in the Premier League in 14 years and Arteta withdrew the ineffective Tavares, starting in place of the injured Kieran Tierney, with Gabriel Martinelli called from the bench for the second half
It took Arsenal 67 minutes to create a meaningful chance against a well-drilled Palace side as Martin Odegaard fired wide from just 10 yards out, but any hope of a comeback was dashed when Odegaard fouled Zaha in the penalty area
The winger dusted himself down and fired home to seal the points
Eddie Nketiah struck the bar with a beautiful late effort but it was just one of those nights for Arteta's lethargic side that not many people will have seen coming
Arteta's team came into this game on the back of five straight away wins, scoring 14 goals along the way
 For the first time in many years, genuine hope has been seen among the fanbase that this young team could take the club back to the heights of yesteryear
So, where did this first-half performance come from? The only outfield change of personnel from their last victory at Aston Villa was at left-back where Tavares replaced the injured Tierney, who suffered a knee injury while on international duty with Scotland after playing in both of their friendlies
Arteta said: "He came back from international duty and he felt something wrong in his knee
 We scanned it and there is some damage there
"He's seeing the specialist on Tuesday and hopefully we will know more but it's not looking good
"It is harsh to say Tavares' inclusion was the reason behind the lack of rhythm of the team but the inexperienced full-back looked miles off the pace - as he did on his last appearance when he was substituted after just 35 minutes in the FA Cup defeat by Nottingham Forest
 It was his indecision, along with Gabriel, that caused the space for Ayew to scamper through and double Palace's lead
"I think Nuno Tavares has to come off," said Jamie Carragher at the break
"He's at fault for the second goal
 But you've got to admire Ayew's goal from Palace's point of view
"As a young player you're taught to think that the player next to you is a dummy or a poor player
 Tavares stops because he thinks Gabriel is going to cut it out but Ayew keeps running
"Tavares' performance was a stark reminder of the work still needed to be done at Arsenal in terms of strengthening their squad
 The 22-year-old was indeed replaced at half-time by Martinelli with Granit Xhaka moving to the left-back spot
 It certainly helped with their performance in the second period but not enough to even threaten a comeback
When asked about if withdrawing Tavares could have a damaging affect on the player's confidence, Arteta said: "Today it was just a tactical reason
 How we could attack and control much better in that position
 I'm sorry that it was Nuno again but we had to do it
"Arteta criticised his team's performance, admitting they did not compete physically with Palace
He told : "Congratulations to Palace for the game they played but we made it impossible for ourselves with the way we competed
"You have to be physical and run and then you earn the right to play
 We were really inconsistent on the ball and that is unacceptable
"We were poor, especially in the first half
 I apologise to our supporters
 We didn't have the presence today or the composure to dominate the situation so that is what I'm most annoyed with
 Some days you are not there and you are late all the time
 They got on top of it and had a good atmosphere and we could not get out
"When we had the big chances we didn't score to give ourselves the best chance to get back in the game
 First of all we need to put our hands up and get the criticism we deserve
 Then we accept it, look ourselves in the mirror and look to the next game
 This was not good enough
"Crystal Palace boss  said: "We played a really good game of football
 We defended well and took our chances
 We scored in important moments of the game
 We needed a big team performance and we did it so we're really pleased
"We wanted to put pressure on and the atmosphere in the stadium allowed us to take that kind of risk
 We were really smart with the way we defended from the front and took the chances to score goals
"This football club is all about supporting the team and when we are at home we really feel that
 The players were tired but the big difference is the atmosphere and the fans behind the players
""Crystal Palace were excellent
 The intensity of Conor Gallagher really rubs off on the other players and you saw a reaction from the others
 I thought 3-0 was deserved if I'm honest
"It could be a damaging result for Arsenal, but I'm sure Mikel Arteta will be working on a reaction and making sure this game is put to the back of their minds
"They've got a lot of important games coming up and they're in pole position still
 I just think they've got so many young players that this might hurt them
 Tottenham have got a little bit more experience which could help them get over the line
""It's a bad night for Arsenal - the way they've lost, not just the three points but I think it's very important they don't panic and there's no hysteria
 They're still in a really good position - a better position than Tottenham and Manchester United
"They've just won five games away from home on the bounce so you're talking about 15 points from 18 away from home