Arsene Wenger marked his 20th anniversary with a lucky stoppage-time against Burnleyat Turf Moor.
Alex Oxlade-Chamberlain struck in the third minute of stoppage with a shot which when in off Laurent Koscielny's arms.
The Burnley fans were outraged by Arsenal's late goal after the fourth official had signalled two minutes of added time and the Clarets hit the post through Michael Keane, while Sam Vokes missed two good chances.
Alexis Sanchez went closest for the Gunners before their controversial late winner and he grazed the post with a volley.
Here are five things we learned...
1. Fans say thank you to Wenger
The Gooners respected Arsene Wenger on his big day. The 'Arsene out' banners from August were replaced by one saying 'thank you' and depicting his three titles and six FA Cups as the travelling fans paid tribute to him on his 20th anniversary.
2. Sanchez needs freedom
Wenger should give Alexis Sanchez a free role. Wenger wants Sanchez to play through the middle as a No 9, but the Chile star only started to cause Burnley problems when he dropped deep.
3. Vokes needs to be clinical
Sam Vokes needs to be more lethal. Vokes is a great targetman for Burnley, but he fluffed two great chances at 0-0 when he missed from a free header and then produced an air kick.
4. Defour struggled against superior opposition
Steven Defour has discovered that Arsenal aren't Watford. Defour was excellent against Watford, but barely made an impression against the Gunners and was taken off just after the hour mark.
5. Ozil is too inconsistent
Mesut Ozil needs to deliver more consistently. Ozil had little effect on the game operating as Arsenal's No 10. He is a world-class talent, but he needs to show it more often.