Arsene Wenger was left celebrating a victory on his 20th anniversary in charge of Arsenal but it was certainly not a vintage display by his team in Lancashire.
A cagey opening between two teams at either end of the table
When Alexis Sanchez saw an effort deflected only inches past Tom Heaton's far post in the fourth minute, it looked as if Arsenal were going to create a barrage of attacks at Turf Moor. Yet a combination of disciplined Burnley defending and lacklustre Arsenal passing proved this was not to be the case in the opening 45 minutes.
When Wenger's teams over the past 20 years have got it right, their passing is irresistible. Though more often than not in the modern era, the Gunners have flattered to deceive and this was to be another occasion. The build-up play was too slow and their main playmaker Mesut Ozil was well off the pace with his passing radar was not tuned in.
Burnley's tactic was one typically deployed by the underdog. They played with ten men behind the ball, leaving Sam Vokes as the target man up front. Yet the Welsh striker struggled to have any sort of impact as he was closely pursued by Shkdoran Mustafi and had no support around him. The Burnley midfield were sitting deep to prevent Arsenal from finding space when they went forward, thus preventing the likes of George Boyd and Steven Dafour from getting close to Vokes.
However the striker did have the best opportunity of the first half. Matthew Lowton picked him out with a chipped cross, only for Vokes to nod wide under no pressure from eight yards. That was to be Burnley's only touch in the Arsenal penalty area of the opening 45 minutes.
Late show from an out of sorts Arsenal
The visitors knew they had to force the issue after the break and came out with much more tempo to their play. Just three minutes into the second half, a spell of precise passing and movement resulted in the ball making it's way to Sanchez who fired an effort at Heaton.
Certainly in the last decade of the two Wenger has overseen, Arsenal have found it difficult to defend against high balls and that was the case again on the hour mark. Johann Berg Gudmundsson rose highest before directing a header that Petr Cech just about managed to palm away.
Then came a couple of moments in a timid contest where both sides could have opened the scoring. Sanchez saw a volley from ten yards clip the post, before Michael Keane headed against the crossbar from a Burnley set piece just seconds later.
Burnley looked as if they were going to hold out for a point before the late drama unfolded. A short corner came to Sanchez who saw his cross flicked on by Walcott. Alex Oxlade-Chamberlain found himself unmarked at the back post before firing the ball at Laurent Koscielny's hand and into the back of the net with the last action of the game.
It certainly wasn't one of Arsenal's best performances over the last 20 years and definitely not one of their trademark type of goals, but it was a crucial anniversary win as Wenger's men moved within two points of the top of the table.