It proved to be a flash of genius as the youngster scored the crucial equalizer immediately and then nabbed the victor in extra time.
He entered the fray in the 85th minute to taunts of "Who are You?" from Norwich supporters, but Edward Nketiah left to chants of "Eddie, Eddie" after making a name for himself with two goals in the first ten minutes of his domestic debut to turn this game around and spare Arsene Wenger's blushes.
Farke's side created plenty of second-half chances to add to Murphy's well-taken opener but failed to beat Arsenal debutant Matt Macey. Wilshere and Coquelin will likely start in the center of the park for Arsenal.
But Farke pointed to an incident after the interval where Elneny escaped a red card after he hauled down Nelson Oliveira as the Portugal worldwide burst through on goal as a key point in the contest.
The hosts toiled in their search for an equalising goal but it was Norwich who passed up a fine opportunity as Oliveira blazed over after being found by Ivo Pinto inside the Gunners' box.
Supreme Court refuses to recall order on National Anthem
The Supreme Court observed that the government can bring in a regulation or ordinance in this regard on the basis of its stand. They were using violence against those not standing up during the playing of the national anthem in cinema halls.
And while the likes of Ainsley Maitland-Niles, Reiss Nelson, Joe Willock, Chuba Akpom, Matt Macey, Ben Sheaf, Jay Dasilva, Eddie Nketiah, Marcus McGuane and Jordi Osei-Tutu will all hope to be in contention to face Norwich, the depth of options now available among Arsenal's senior ranks appears to hint at a slightly different direction for this year's edition.
Wilshere could have won the match in normal time, being brilliantly denied by Gunn from five yards out, while substitute Chuba Akpom also came close.
The Canaries then had a decent shout for a penalty, with Mathieu Debuchy getting away with a clumsy challenge on James Husband.
The visitors were all but out on their feet and could not find an equaliser as Arsenal saw the game out to progress to the quarter-finals.
Subs not used: Martin, Franke, McGovern.