Ben White was making his return to the starting XI after recovering from injuryArsenal's hopes of finishing in the Premier League top four were dealt a huge blow as they were well beaten by Newcastle at St James' Park.
Mikel Arteta's side needed a win to move above Tottenham into fourth and put them in the driving seat to secure a Champions League spot heading into the final weekend of the season.
But they were second best throughout and fell behind early in the second half when Ben White turned the ball into his own net under pressure from Callum Wilson, who was making his first start since 27 December.
Bruno Guimaraes, who has become a cult hero since joining Newcastle at the start of this year, then rounded off the impressive win when he drove into the net as Arsenal struggled to clear.
Arsenal offered next to nothing, with Martin Dubravka only really tested once, with a 25-yard Mohamed Elneny shot in the second half.
Indeed, Newcastle could have won by more with Wilson coming so close to capping a dream return from injury with a stunning long-range effort that dropped just wide of the goal.
The result, which also confirmed Chelsea's finish in the top four, means Arsenal must beat Everton in their final game of the season on Sunday (16:00 BST) and hope Tottenham lose at relegated Norwich.
Newcastle, meanwhile, round off a season that provides encouragement for the future with a trip to Burnley.
Arsenal needed to show up but failed
Arsenal needed a big performance if they were to give their fans hope of finishing in the top four, particuarly after they were well beaten by their fierce rivals Tottenham in last Thursday's north London derby.
Unfortunately, Arteta's side wilted when it mattered most as they were outplayed by Newcastle.
The Gunners were poor throughout the first half as they repeatedly gave the ball away and were having to repel a stream of Newcastle attacks while struggling to build their own opportunities.
They managed to get to get to half-time level but did not heed the warning signs and fell behind just before the hour mark.
Wilson had been a menace throughout as he showed no signs of rustiness on his return to the first team. It was no surprise he was involved in the opener as White turned the ball into his own net as he attempted to prevent the Newcastle forward from getting a shot off.
Arteta was unable to hide his frustrations with the officiating against Spurs - a match in which his team conceded a penalty and had defender Rob Holding sent off - but he can have no complaints here as they were undone by a side who simply showed more hunger and quality.
Player of the match
WilsonCallum Wilson
Newcastle United
Squad number9Player nameWilson
Squad number39Player nameBruno Guimarães
Squad number7Player nameJoelinton
Squad number13Player nameTargett
Squad number24Player nameAlmirón
Squad number10Player nameSaint-Maximin
Squad number33Player nameBurn
Squad number5Player nameSchär
Squad number6Player nameLascelles
Squad number21Player nameFraser
Squad number36Player nameS Longstaff
Squad number17Player nameKrafth
Squad number23Player nameMurphy
Squad number1Player nameDúbravka
Squad number34Player nameGayle
Line-ups
Newcastle
Formation 4-3-3
1Dúbravka
17Krafth5Schär33Burn13Targett
36S Longstaff39Guimarães Rodriguez Moura7Joelinton
24Almirón9Wilson10Saint-Maximin
1Dúbravka17Krafth5SchärSubstituted forLascellesat 49'minutes33Burn13Targett36S Longstaff39Guimarães Rodriguez Moura7Joelinton24AlmirónSubstituted forMurphyat 76'minutes9WilsonSubstituted forGayleat 90+4'minutes10Saint-MaximinSubstituted forFraserat 77'minutesSubstitutes
3Dummett6Lascelles11Ritchie15Trippier18Fernández21Fraser23Murphy26Darlow34GayleArsenal
Formation 4-2-3-1
32Ramsdale
18Tomiyasu4White6Gabriel20Tavares
25Elneny34Xhaka
7Saka8Ødegaard10Smith Rowe
30Nketiah
32Ramsdale18TomiyasuSubstituted forCédric Soaresat 39'minutes4WhiteBooked at 8mins6GabrielSubstituted forPépéat 73'minutes20TavaresSubstituted forLacazetteat 62'minutes25Elneny34XhakaBooked at 90mins7Saka8Ødegaard10Smith RoweSubstituted forMartinelliat 53'minutes30NketiahBooked at 46minsSubstitutes
1Leno9Lacazette17Cédric Soares19Pépé23Sambi Lokonga35Martinelli65Oulad M'hand69Swanson87PatinoReferee:Darren EnglandAttendance:52,274Live Text
Match ends, Newcastle United 2, Arsenal 0.
Second Half ends, Newcastle United 2, Arsenal 0.
Attempt missed. Dwight Gayle (Newcastle United) right footed shot from the right side of the six yard box is too high. Assisted by Sean Longstaff.
Attempt saved. Ryan Fraser (Newcastle United) right footed shot from the centre of the box is saved in the bottom right corner. Assisted by Dwight Gayle.
Granit Xhaka (Arsenal) is shown the yellow card for a bad foul.
Bruno Guimarães (Newcastle United) wins a free kick in the defensive half.
Foul by Granit Xhaka (Arsenal).
Substitution, Newcastle United. Dwight Gayle replaces Callum Wilson.
Attempt missed. Cédric Soares (Arsenal) right footed shot from outside the box is high and wide to the right. Assisted by Mohamed Elneny.
Corner, Arsenal. Conceded by Dan Burn.
Attempt blocked. Bukayo Saka (Arsenal) right footed shot from outside the box is blocked. Assisted by Benjamin White.
Callum Wilson (Newcastle United) wins a free kick in the defensive half.
Foul by Martin Ødegaard (Arsenal).
Goal! Newcastle United 2, Arsenal 0. Bruno Guimarães (Newcastle United) right footed shot from the centre of the box to the top right corner.
Attempt blocked. Bruno Guimarães (Newcastle United) right footed shot from outside the box is blocked. Assisted by Callum Wilson.
Bruno Guimarães (Newcastle United) wins a free kick in the defensive half.
Foul by Gabriel Martinelli (Arsenal).
Attempt blocked. Martin Ødegaard (Arsenal) left footed shot from the centre of the box is blocked. Assisted by Eddie Nketiah.
Attempt missed. Callum Wilson (Newcastle United) right footed shot from more than 35 yards is close, but misses to the right. Assisted by Martin Dúbravka.
Foul by Joelinton (Newcastle United).
Our coverage of your Premier League club is bigger and better than ever before - here's everything you need to know to make sure you never miss a moment
