After the toxic atmosphere of recent weeks diminished somewhat after a semi-final victory over Manchester City at Wembley on Sunday, Gunners boss Arsene Wenger looked like being brought back down to earth by the Foxes.
However, Nacho Monreal's late effort flew in off the unwitting Huth to seal a nervy 1-0 home win.
Until that point, the hosts had been kept at bay by a well-drilled Leicester defence and some smart saves from Kasper Schmeichel.
James Olley assesses the key talking points from the Emirates...
Arsenal keep their top four hopes alive
Manager Arsene Wenger called on his side to deliver the perfect run-in with seven successive wins to keep their top four hopes alive and they scrambled the first of them with an 86th-minute own goal to beat Leicester.
With at least one of the Manchester clubs set to drop points in tomorrow’s derby, a victory was paramount for Arsenal to capitalise.
The Gunners moved within four points of fourth-placed Manchester City with a scrappy victory that at least displayed their hunger to fight until the end, even if the goal was fortuitous in its arrival.
One thing is for sure: Arsenal will have to play much better to keep the run going against Tottenham in Sunday’s north London derby.
Arsenal’s FA Cup run hasn’t dented fan apathy
The Gunners produced one of their best performances of the season in beating Manchester City at Wembley on Sunday but it did not encourage a strong turnout here against Leicester.
Exact figures are always difficult to quantify as Arsenal’s official attendances are based on tickets sold but the ground was well short of capacity, even allowing for the mitigating circumstance of a midweek kick-off.
The Arsenal Supporters Trust estimated this was the lowest ever crowd for a competitive game at Emirates Stadium and while that is unverifiable at this stage, the apathy that has engulfed the red half of north London in recent weeks has not dissipated.
3-4-3 fails to bear fruit
Arsenal had won both matches since switching to three at the back and Wenger deployed it once more against Leicester, albeit it with four changes in personnel.
Arsenal created a few first-half chances as Leicester rode their luck at times – Alexis Sanchez was unlucky with a long range effort that struck the crossbar just before the break – but they often struggled to find space against the visitors’ compact defence.
Wenger waited until the 68th minute before changing to a back four with Danny Welbeck’s introduction, before Aaron Ramsey and Olivier Giroud came on seven minutes later as Arsenal went for broke.
Fringe players fluff their lines
Nacho Monreal was switched to centre-back and with Alex Oxlade-Chamberlain only fit enough following a foot injury to make the bench, Hector Bellerin and Kieran Gibbs were given a chance to impress in wide areas.
Gibbs, in particular, has mitigation given he hasn’t played for more than six weeks and was understandably rusty while Bellerin’s underwhelming form continued on the opposite flank.
On this evidence, Monreal and Oxlade-Chamberlain are nailed on to start as wing-backs this weekend if Wenger persists with a 3-4-3 shape.
Francis Coquelin did little wrong given he was selected to stifle Leicester’s counter-attacking raids but Arsenal lacked creativity in central areas.
Walcott misses chance to play a central role
Danny Welbeck’s lively cameo in place of Giroud at Wembley made Walcott’s selection from the outset something of a surprise here.
Walcott was unable to use his blistering pace against a Leicester team that sat deep for long periods and after two games on the sidelines, the 28-year-old struggled with his decision making in the final third.
The crowd called for Welbeck’s introduction early in the second half but it was Giroud who replaced him with 15 minutes left.