The 30-year-old powered clear of Tyneside-based Ethiopian Yared Hagos and Ireland's Stewart Scullion over the final kilometre in the capital to reach the finish in Holyrood Park in 30 minutes and 18 seconds.
After having failed to win the event on two other occasions, including in a runner-up finish last year, the victory was another boost to his hopes of qualifying for Scotland's Commonwealth Games team.
"Last year when I ran I put everything on the line and came up short so it was great to be able to win," said Lemoncello. "I felt tired as I didn't get much sleep because of the jet lag, so I'm just glad I managed to pull it off."
Two-time Olympian Jen Rhines dominated the women's race, leading from start to finish to become the first American winner since Deena Kastor in a time of 34:22.
"The atmosphere was fantastic though and it's just a been a beautiful day," she said. "This was my first road race in Europe, so that makes it extra special but I expect to be back racing in the Bupa Great Run series soon."