Arsenal were booed off the pitch after a second humiliation in two months against lower league opponents when visitors Blackburn Rovers beat them 1-0 in the FA Cup fifth round with a late Colin Kazim-Richards goal on Saturday.
Manager Arsene Wenger's gamble of leaving out a batch of first-team regulars against the Championship (second tier) side backfired as Arsenal fan Kazim-Richards struck a 72nd minute winner to send Rovers into the quarter-finals.
Arsenal's Czech Republic midfielder Tomas Rosicky had come closest to breaking the deadlock with a thumping shot against the bar and Rovers had to survive furious pressure as the hosts belatedly showed some urgency, but it was too little too late.
"It's painful and disappointing to lose," Wenger, whose side fell to fourth-tier Bradford City on penalties in the League Cup quarter-finals, told reporters after another low point in what has become one of his most difficult seasons at the club.
"We lacked ruthlessness and calm in front of goal and didn't make enough of our corners and in the end we were vulnerable to one mistake. We weren't good enough to win the game today."
With Arsenal 21 points off the Premier League pace in fifth, a poor result at home to Bundesliga leaders Bayern Munich in their Champions League last 16, first leg on Tuesday would virtually guarantee an eighth straight trophy-less campaign.
Unusually no top flight club is definitely yet through to the FA Cup quarter-finals in what is becoming a vintage year for less-fancied sides after Everton were held 2-2 having conceded a last-gasp goal at lowly third-tier club Oldham Athletic.
After eliminating Liverpool in the previous round, Oldham's luck seemed to have run out as strikes from Victor Anichebe and Phil Jagielka put Everton 2-1 ahead but Matt Smith's stoppage time header sparked wild celebrations at Boundary Park.
Three Championship sides are through after Millwall ended Luton Town's hopes of becoming the first minor league club to reach the quarter-finals for 99 years with a 3-0 victory while Barnsley were comfortable 3-1 winners at MK Dons.
Manchester City welcome Leeds United and holders Chelsea have a fourth round replay with visitors Brentford on Sunday while Premier League leaders Manchester United play Reading at Old Trafford on Monday.
Wenger made seven changes to the Arsenal side that won at Sunderland in the Premier League last week, leaving the likes of Jack Wilshere, Theo Walcott and Santi Cazorla on the bench.
Ironically, it was just after that trio had been introduced to try and inject some firepower to a powder-puff display with 20 minutes left that Rovers scored from a rare foray forward.
A long punt found Martin Olsson in space and when his fierce shot was only parried by Wojciech Szczesny, London-born Kazim-Richards, on loan from Turkish club Galatasaray, scuffed the ball into the ground and watched it bounce in off the post.
"It was not the sweetest of strikes," said Rovers manager Michael Appleton, with his third club in this season's FA Cup having started at Portsmouth before a brief stint at Blackpool.
"In fairness he tried to keep the ball down because it could have ended up in Row Z, and he got the luck he deserved."
With disgruntled Arsenal fans already heading for the exits, one shouting "You disrespect the Cup Wenger", the Gunners bombarded Rovers' goal but the visitors stood firm.
Wenger said his team selection was no excuse for the club's first loss to lower league opponents in the FA Cup since he took over in 1996.
"We had 11 internationals on the pitch at the start and when we made the changes it was 0-0," said the Frenchman. "We had a lot of the ball and they defended well. But we made a massive mistake on the goal."
Despite 26 goal attempts, Arsenal can hardly count themselves unlucky as, apart from the final 15 minutes, there was a lack of urgency about their display.
Blackburn, relegated from the Premier League last season, had one early chance when Marcus Olsson shot across goal but it was mainly Arsenal possession without any cutting edge.
Rovers' Jake Kean made one flying save to keep out a header from Abou Diaby and Gervinho wasted a great opportunity just before halftime, pulling his shot wide after being sent clear by Rosicky, as Arsenal failed to make the most of their chances.
"It's important now to focus on the next game and it's an opportunity to show we have character and that we are men who fight for each other," Wenger added.