Arsenal's top-four hopes took their second big hit of the week as Brighton held on during a dramatic finish to end a seven-game winless run with a deserved 2-1 victory at the Emirates Stadium on Saturday
The Gunners were way below the required standard during Monday night's 3-0 defeat at Crystal Palace but there was no positive response five days on as Leandro Trossard (28) punished another tame opening spell from Mikel Arteta's side
Gabriel Martinelli had a header on the stroke of half-time scrubbed off when VAR eventually judged him to be offside in an extremely tight call but Enock Mwepu converted a fine half-volley (67) to put Brighton in control
Brighton's travelling support were bouncing in their corner of the Emirates after that - they'd only seen their side score once during their wait for a win - but their nerves were plain to see during a frantic finale after Martin Odegaard's deflected long-range hit (89) led to Arsenal finally upping the intensity in search of a last-gasp equaliser
Robert Sanchez pulled off a sharp stop from Eddie Nketiah deep into injury-time to ensure there was no comeback, though, and Brighton move up to 11th after another frustrating outing for Arsenal followers
 They've missed the chance to move fourth twice this week and it's now three defeats in four in the league
 on , moving three points clear in fourth, although they have played a game more
 Meanwhile, Arsenal will ponder a run of games which sees them face Chelsea, Manchester United and West Ham in three of their next four games with a stretched midfield
The derby between Arsenal and Tottenham, now scheduled for May 12 could well be decisive in the race for a place in Europe's top club competition next season - but with Arsenal again open at the back and disjointed in attack they could well be out of the picture by then anyway
Arteta had called on his team to bounce back after an awful first half led to a bad defeat at Selhurst Park but his men were slow out of the blocks again
 Brighton may not have hounded them in the same way as Patrick Vieira's side but there were groans from the home support as passes missed targets
Set pieces have been Arsenal's most likely route to goal of late and Gabriel Magalhaes headed narrowly wide on 26 minutes - but his team fell behind inside the half-hour mark once again soon after
Xhaka's selection at left-back ahead of Nuno Tavares was a big talking point before kick-off and the midfield regular was absent when Mwepu darted down that channel before pulling back for Trossard to slam in his fifth of the season
There was controversy just before half-time when Martinelli thought he'd pulled one back from another set-piece - but after a VAR check lasting four minutes, he was eventually judged to be narrowly offside from Gabriel's nod back across goal
A scrappy start to the second half saw Bukayo Saka booked for diving and Moises Caicedo shown a yellow for chopping down Odegaard but Arsenal, for the first time in the match, began to build some sustained attacks, with Saka lashing over from the edge of the box after a corner
However, just as the hosts were putting the squeeze on, Brighton hit a super second, with Mwepu - like Trossard in the first half, picked out in space on the edge of the box - brilliantly steering Caicedo's cut-back into the bottom corner
It fell very flat at the Emirates at that point and it wasn't until Albert Sambi Lokonga swerved one narrowly wide on 86 minutes that Arsenal really threatened
That seemed to inspire his team-mates and Arsenal hit the bar twice in quick succession, first from Odegaard's free-kick and then from Nketiah's follow-up, before Odegaard's effort looped off former Gunner Danny Welbeck and into the net
Arsenal surged forwards in search of one more but after Lokonga and Saka shot straight at Sanchez the goalkeeper's super stop from Nketiah sealed the victory for the visitors
"The first half we didn't have the reaction I expected
 We were sloppy, unprecise
 We were not with the right approach and right courage to play the way we want to play
 The game was there and we were cold
 We didn't transmit any energy, we didn't transmit any willingness to dominate the game the way we want to do it
 The first situation they had they scored a goal
 The second half we had a reaction, especially in the last minute
 It's great not to give up but we had to do it in the first minute
"We were really unprecise, and we didn't have the speed or purpose or courage to attack the way we wanted to attack
 We were really predictable with what we wanted to do and then unprecise
 Everything isn't going to be smooth in a season
 You're going to have a moment where you don't perform individually and collectively, that's fine
 But then you need to react and today we didn't show that in the first half
""That was a big moment because that would have changed the game
 The momentum and the energy
 When you're not playing so well you need something to go your way and we hit the bar twice and the keeper made some excellent saves
 It didn't happen but it's down to us
""It's a fantastic feeling
 That game showed how difficult it is to get three points in the Premier League, especially away from home against a team challenging for the top places
 It's fantastic for the boys, really pleased for them, the performance was really good and the result is even better
"We needed a bit of luck, our goalkeeper to make saves
 But you need those things to win matches in the Premier League
 It was important we kept trying to push, we had to weather the storm a bit and suffer
 The second goal was really important
 We had to hold on
 We're humble enough and honest enough to know the Premier League is the toughest competition you can have
 Nothing is easy
"I was very happy with the disallowed goal! I'd rather it takes less time but if it goes in our favour they can take as long as they want!""You can't worry what people say from outside, you have to carry on with your work and we've been happy with the progress
 We have to keep on improving
 We've said all along we'll fight for every point and we want to finish as strongly as we can
 This gives us a platform to push the team on
 It's a good day but there's more to come
 It's a massive result for us
"Only a couple of weeks ago it felt as though Arsenal were favourites to land fourth place and a long-awaited return to the Champions League
 But in the space of six days their hopes of returning to Europe's top club competition have suffered a significant blow
The defeat to Crystal Palace on  was a bad one
 Arsenal, harassed and harried by their London rivals, never got going and made costly mistakes
 It was the worst performance they'd served up since the early weeks of the season
A young side is prone to inconsistency, though, and the real issue was not that loss but how they'd respond
 The answer Arsenal fans saw on Saturday would have alarmed them
While Brighton didn't bring the same frantic pressing style to the Emirates that Palace showed at Selhurst Park, Arsenal were still slow out of the blocks again, sloppy in possession and disjointed in attack, with the forced reshuffle caused by Thomas Partey's absence and Nuno Tavares' form not working
Gabriel Martinelli was denied an equaliser by a marginal offside call on the stroke of half time but that would have been harsh on Brighton
 It wasn't until Martin Odegaard made it 2-1 in the 89th minute that Arsenal showed the required intensity levels
With injuries, fixtures and points totals now counting against them, Arsenal have it all to do if they are to overhaul neighbours Tottenham in the race for fourth
 Come the summer, they may look back on this week as the moment their encouraging season unravelled
April 16 - April 20 - , April 23 - May 1 - , May 8 - , May 12 - , May 16 - May 22 - Brighton return to Premier League action next Saturday at Tottenham; kick-off 12
30pm
 The Seagulls visit Manchester City just four days later on Wednesday April 20 at the Etihad Stadium
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