La Roja needed a late winner from Alvaro Morata to beat the Blågult 1-0, which was probably the right result as chances were few and far between on the night.
Janne Andersson's side, who were runners-up in Group G, now face an agonising wait to discover their opponents in the play-offs.
But one eagle-eyed journalist spotted the moment that Zlatan Ibrahimovic rather awkwardly careened into the Chelsea captain with two seconds left on the clock, leaving the right-back in some obvious discomfort.
As the players waited for a corner, Ibrahimović appeared to accidentally bash his elbow into the back of Azpilicueta, who immediately fell to the ground in agony.
Ibrahimovic, 40, had only entered the fray 15 minutes earlier, but still found plenty of time to leave his mark.
However, the incident went unpunished, as VAR decided not to intervene.
WATCH: Zlatan Ibrahimovic accidentally catches Cesar Azpilicueta with an elbow in the back
Check out the video below...
Whether intentional or not, it was evidently quite a painful one for the Spanish defender, who fell down like a sack of potatoes. Ouch.
Thankfully for Blues fans it didn't take long for Azpilicueta to shake off the knock, as he gingerly got back to his feet shortly before the final whistle blew only moments later.
Blues boss Thomas Tuchel will no doubt be keeping his fingers crossed Azpilicueta reports fit for duty at Cobham ahead of a busy run of fixtures in the run-up to Christmas next month.
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