Arsene Wenger endured a woeful 1,000th game in charge of Arsenal as Premier League leaders Chelsea romped to a 6-0 win at Stamford Bridge.
The Frenchman has never tasted victory over Chelsea boss Jose Mourinho and that record continued on Saturday as Arsenal were taken apart in embarrassing fashion.
Samuel Eto'o and Andre Schurrle capitalised on poor defending to put the hosts two goals ahead inside seven minutes.
Things soon got worse for Arsenal as Alex Oxlade-Chamberlain handled on the line after 15 minutes to concede a penalty that Eden Hazard converted, with Kieran Gibbs bizarrely sent off by referee Andre Marriner following an apparent case of mistaken identity.
Oscar then added further goals either side of half-time and substitute Mohamed Salah also got in on the act to round off a day that must rank among the worst of Wenger's lengthy tenure.
Arsenal now sit seven points behind Chelsea having played a game fewer, and their dismal performance continued a worrying trend this season in away matches against title rivals.
Wenger's side had already suffered 6-3 and 5-1 defeats at the hands of Manchester City and Liverpool respectively and now appear likely to complete another season without a Premier League title.
Schurrle and Eto'o were each recalled, together with David Luiz, to a Chelsea side missing Ramires and Willian through suspension.
An unchanged Arsenal threatened after four minutes when Olivier Giroud forced Petr Cech into a sharp low save following a neat throughball from Tomas Rosicky.
Yet Chelsea then moved ahead almost immediately as a swift counter-attack ended with Schurrle switching the ball right to Eto'o, who cut inside Oxlade-Chamberlain before curling a delightful shot past Wojciech Szczesny.
Arsenal soon found themselves horribly exposed once again. Nemanja Matic dispossessed Santi Cazorla before finding Schurrle and the German forward capitalised on defenders backing off by firing into the bottom-left corner.
Remarkably, the visitors' first-half display had yet to reach its nadir and Hazard added a third Chelsea goal from the penalty spot after his shot had been handled by Oxlade-Chamberlain.
Referee Marriner chose to dismiss Gibbs for the offence, despite Oxlade-Chamberlain appearing to confess his guilt.
The game was effectively over as a contest following the sending-off and Chelsea pulled further clear after 42 minutes when Fernando Torres, an early replacement for the injured Eto'o, crossed from the right for Oscar to convert.
Neither Oxlade-Chamberlain nor Laurent Koscielny emerged for the second half, which began with Szczesny denying Luiz after more good work from the lively Torres.
Cazorla dragged a shot narrowly wide on the hour mark, before another Arsenal error led to Chelsea scoring again in the 66th minute.
A sloppy pass from Rosicky found Oscar and the Brazilian beat Szczesny with a low strike that the goalkeeper may feel he should have saved.
Mourinho's men were not finished there and Salah, who had only just come on for Oscar, made it 6-0 five minutes later, beating the offside trap to break clear and score his first goal since arriving from Basel.
That ensured Chelsea scored six in a Premier League game for the first time under Mourinho, emphatically spoiling Wenger's landmark day.
|Coach: José Mourinho|
for S. Eto'o 10'
for Oscar 67'
for David Luiz 72'
|Juventus unveil dramatic change to club logo - but not everyone´s a fan|
|´I do not think I will return to coaching´ - Van Gaal set to call it quits|
|Torino 2 AC Milan 2: Bacca caps thrilling comeback as hosts pay the penalty|
|DR Congo 1 Morocco 0: Kabananga pounces on blunder to give 10 men the points|
|´Happy and comfortable´ Sanchez dismisses Arsenal exit talk|
|How much?! West Ham flop Simone Zaza could cost Valencia €20m|
|Mali v Egypt: Salah leads Pharaohs´ bid for AFCON glory|
|Sevilla concede they ´cannot force´ sporting director Monchi to stay|
|Ivory Coast 0 Togo 0: Reigning champions held to opening draw by Adebayor and co.|
|Goalkeeping woes, Stones and tactical confusion - How Guardiola is making life difficult for himself|
|Ozil and Sanchez can be persuaded to stay - Cech|
|Pogba: I rejected Barcelona and Real Madrid|
|Ghana v Uganda: Gyan dreams of first trophy since 1982|
|Chiellini: Juventus a work in progress|
|Robben agrees Bayern renewal until 2018|
|Hazard: Goals do not matter to me|
|Bennell pleads not guilty to eight child sex offences|
|Muller fed up with debate over Bayern role|
|Wenger glad Sanchez is not ´a Costa problem´|
|Flick resigns as DFB´s sporting director|
|Gomis ´can´t wait´ to welcome Payet to Marseille|
|Chinese FA changes foreign player rules after ´irrational´ spending|
|Like father, like son: Justin Kluivert follows in dad´s footsteps|
|´No reason to lose him´ - Marotta rubbishes talk of Allegri exit|
|Courtois: We don´t need Costa|
|Kane: Tottenham players won´t go to China|
|Noble ´angry and disappointed´ with Payet|
|Klopp furious over Matip uncertainty|
|Wenger surprised by tight Premier League|
|´Money is not everything´ - Conte issues warning amid China speculation|
|Fiorentina defeat a ´bad setback´ - Allegri|
|´This will elevate this group of players´ - Sampaoli revels in Sevilla late show|
|WATCH: Rio Ferdinand screams and dances in crazy Man Utd celebration|
|Real Madrid relaxed, admits Zidane after Sevilla defeat|
|Monaco go top of Ligue 1 with stunning Marseille victory|
|Ronaldo equals LaLiga penalty record as Real Madrid lose|
|Sevilla 2 Real Madrid 1: Stunning late comeback ends unbeaten run at 40|
|Fiorentina 2 Juventus 1: Brilliant Viola breathe life into Serie A title race|
|Tunisia 0 Senegal 2: Mane on target as favourites start strongly|
|Mourinho explains Klopp confrontation|
|Klopp delights in Alexander-Arnold display|
|Algeria must cut out mistakes against Tunisia - Leekens|
|Long balls led to Man Utd equaliser, says Klopp|
|´We attacked, Liverpool defended´ – Mourinho insists a point flattered Klopp´s men|
|DR Congo v Morocco: ´Confidence´ the Atlas Lions´ biggest hindrance ahead of AFCON opener|
|Ibrahimovic: Direct tactics worked for United|
|Guardiola rues gap to Chelsea after Goodison mauling|
|Algeria 2 Zimbabwe 2: Mahrez double prevents shock defeat|
|Manchester United 1 Liverpool 1: In-form Ibrahimovic saves hosts|
|Ivory Coast v Togo: AFCON champions hope to tame Le Roy´s ´troublemakers´|
|Guardiola lays City´s mental frailties bare after Goodison rout|
|Koeman hails ´perfect´ Everton after City mauling|
|Nice stalemate gives Monaco chance to go top|
|Guardiola suffers heaviest league loss in Everton thrashing|
|Neymar-esque Zaha is England´s loss – Bolasie|
|Everton 4 Manchester City 0: Koeman leaves old pal Guardiola´s title bid in tatters|
|Matip withdrawn from Liverpool selection over eligibility questions|
|Podolski staying at Galatasaray, insists sporting director|
|Cavani wants PSG stay|
|Torino move feels normal now – Hart|
|Chinese FA changes rule on CSL foreign players - reports|
|Bayern complete swoop for Hoffenheim duo Sule and Rudy|
|Aubameyang: Dortmund not really like Barca, Madrid or Bayern|
|Pogba can chance a game in one second - Herrera|
|Newcastle Jets 2 Perth Glory 2: Keogh´s eighth of season seals draw|
|Klopp: Liverpool ready for Old Trafford test|
|Herrera taunts Liverpool ahead of Old Trafford showdown|
|I had to be 100 per cent to stay at Boca - Tevez|
|No player is bigger than the club - Carroll takes swipe at want-away Payet|
|Icardi: I can always move to China at end of career|
|Mkhitaryan: Klopp convinced me not to join Liverpool|
|Mourinho: Pogba can score every game|
|Cameroon´s profligacy frustrates Broos|