"Thank you, Los Angeles," Garcetti posted on his Twitter page at 2:52 a.m. Wednesday. "The hard work begins but I am honored to lead this city for the next four years. Let's make this a great city again."
City Controller Wendy Greuel called Garcetti early Wednesday to concede the election, a Greuel campaign source told the Los Angeles Times.
Greuel led by a slight margin as returns started coming in Tuesday but saw her lead evaporate through the night, the Times said. With nearly 73 percent of precincts reporting, Greuel had fallen 8 percentage points behind Garcetti.
The source told the Times that when Greuel saw she was trailing Garcetti 54 percent to 46 percent, she called to concede.
"It was positive," the source said.
Garcetti, at age 42, will be the youngest LA mayor in more than 100 years.
Garcetti will take office July 1. He succeeds Antonio Villaraigosa, the city's first Latino mayor in modern times, who served the maximum two terms.
Notable deaths of 2014 [PHOTOS]