Nothing but three points would have sufficed for the Gunners, who were made to work tirelessly against Craig Shakespeare’s well-drilled outfit. The Foxes came to play on the counter-attack and spent much of the game in their own half but Nacho Monreal's 86th-minute shot deflected off Robert Huth's chest and into the back of the net to give Arsene Wenger's men the victory that they so badly required.
Sunday’s north London derby against Tottenham represents arguably the biggest game of Arsenal’s season so far and, following their arch-rivals' 1-0 win over Crystal Palace, there is now the very real of possibility of there being no St Totteringham’s Day for the first time in 21 years.
"In life you work for your own achievements, not for others," said Wenger when asked how important it is to end Tottenham's title hopes.
"It’s important that we go there to focus on our game and our own performance."
Arsenal had won each of their last 10 Premier League home encounters with Leicester City - the longest current run in the division - and that feat never looked like changing as the Gunners incessantly attacked the solid blue wall erected before them on Wednesday night.
Granit Xhaka’s 91.8 per cent passing accuracy rate was even more impressive when you look at how the Swiss international dominated the midfield and attempted to get things moving with lofted balls through to the likes of Mesut Ozil and Alexis Sanchez.
Sanchez himself lost possession 18 times in the game and was particularly wasteful with some of his passing, but the infectious work rate which clearly endears him to so many potential suitors is a facet of his game which often papers over any negatives in his game.
Wenger’s side have now won back-to-back Premier League matches for the first time in over three months and the recent change in formation has been suggested as the main reason behind the improved form.
Despite a host of changes in the starting line-up, including an underwhelming performance at left wing back from Kieran Gibbs, there was a sense that Arsenal needed to stay with their patient approach and wait for the right moment against Leicester.
In the end, it was a familiar scene of 1-0 to the Arsenal. It was a hard-fought win to keep Wenger’s side in the race for a top-four spot and maintain the high morale after Sunday’s FA Cup semi-final triumph against Manchester City.
Next up, though, is the small matter of the final north London derby at White Hart Lane, a match which could make or break Arsenal's European hopes - and their proud record of having finished above their rivals every year since 1996.