Arsenal's failure to deal with long-throw specialist Rory Delap's deliveries could have ended their hopes of the English Premier League title following a 2-1 defeat away to Stoke City.
And Saturday's defeat at the Britannia Stadium was compounded for Arsenal by the way in which they finished the game down to nine men after Dutch striker Robin van Persie was red-carded and England winger Theo Walcott stretchered off
Goals from Ricardo Fuller of Jamaica and Nigerian midfielder Seyi Olofinjana secured a famous victory for Stoke and sent Arsenal, who face Manchester United at the Emirates next Saturday, crashing to their third league defeat of the season.
It meant they were six points behind leaders Chelsea and Liverpool before the Reds kicked-off later Saturday away to Tottenham Hotspur. Even more worrying than this result for Arsenal was the manner of their defeat, which involved an abject surrender against a team billed as the favourites to be relegated this season.
After throwing away a 4-2 lead to draw 4-4 with bitter rivals Spurs in midweek, this was always going to be a test of Arsenal's resolve.
But the Britannia Stadium is perhaps the most raucous arena in the Premier League and one made less inviting on a cold November day.
With captain William Gallas sidelined with a hamstring injury, the Gunners were already without their on-field general before a ball had even been kicked. Gallas's leadership skills have been questioned in recent months, but the France defender would surely have stiffened Arsenal's shaky defence as they struggled to cope with Stoke's direct approach.
Delap's ability is no longer a secret with six of Stoke's 12 goals prior to this game coming from the Irishman's throw-ins. But it is unlikely that any team has defended the throw-ins as poorly as Arsenal, who conceded the first goal to Fuller in the 11th minute after failing to clear Delap's missile-like throw.
Kolo Toure's failure to mark Fuller correctly allowed the Jamaican to glance a header into the far corner of Manuel Almunia's.
Toure and Arsenal manager Arsene Wenger protested that Fuller had won the header as a result of a foul, but they were clutching at straws.
Arsenal just could not get going and Delap almost doubled the home side's lead in the 19th minute when his header from Almunia's miscued punch was cleared off the line by defender Gael Clichy.
The farcical nature of that Stoke chance summed up Arsenal's performance, but although they spent lengthy periods of the second-half camped in the opposition half, they hardly looked like equalising.
Gunners striuker Emmanuel Adebayor looked particularly lacklustre and it was no surprise when he went off, apparently injured, in the 72nd minute.
Just sixty seconds later, the game was all over for Arsenal when Wenger's team failed once again to deal with a Delap throw-in.
Ryan Shawcross's header at the near post dropped to Olofinjana inside the six-yard box and the midfielder bundled the ball over the line with his chest.
Game lost, the day went from bad to worse when substitute van Persie, minutes after coming, was dismissed by referee Rob Styles for crudely barging goalkeeper Thomas Sorensen to the ground.
And the sight of Walcott being stretchered off in stoppage time with a suspected shoulder injury, before Gael Clichy's late consolation strike, capped Arsenal's terrible day.