The Amazing Spider-Man #150 (1975)
Writer: Archie Goodwin
Artist: Gil Kane
Spider-Man goes to Dr. Connors to do tests to see if he is the Clone. He is attacked by Vulture, Sandman and the Kingpin, but these are just robots created by Dr. Spencer Smythe who attacks with a new Spider-Slayer. Spider-Man defeats him and proves to himself that he is not the Clone because, despite he and the clone having the same memories, he has feelings for Mary Jane which could only be based on shared experiences after the death of Gwen Stacy. Thus, he must be the real thing. Spider-Man decides to not read Dr. Connors’ lab report.