Garcetti is the highest-profile elected official to back Duran's come-from-behind run, calling the West Hollywood council member and former mayor an "innovative and thoughtful problem solver."
“John isn’t afraid to make the tough choices, and as our next Supervisor, we can count on him to be a watchdog over county government by ensuring we are getting the most from our tax dollars,'' Garcetti said in a statement.
Duran has served on the West Hollywood council for 14 years as it transitioned from a gritty, new municipality of 37,000 to a haven of boutiques, trendy restaurants and improving civic services.
The criminal defense attorney has positioned himself as the most fiscally conservative of his two chief rivals, former state lawmaker Sheila Kuehl and former Santa Monica council member and mayor Bobby Shriver, in Tuesday's primary elections.
He supports contracting out more county services to the private sector, pushing more county funding to the city level and moving rapidly to expand the region's public transit lines.
Duran has also been endorsed by former state lawmaker David Roberti and by the Los Angeles Times. He faces an uphill battle next week because both Kuehl and Shriver are better funded and better known to voters in Yaroslavsky's 3rd District covering the Westside and much of the San Fernando Valley.
Kuehl has been endorsed by the Los Angeles County Democratic Party, the California Nurses Assn., the National Organization for Women and several state and local lawmakers. Shriver is backed by the Los Angeles and Hollywood business chambers, the San Fernando Valley Young Democrats and former state Assembly speaker Bob Hertzberg.
Duran said he's known Garcetti, a former Los Angeles councilman, since 2001, when both were elected to public office. They served in adjoining districts as Garcetti represented Hollywood next to West Hollywood.
Both were also early supporters of Barack Obama and Duran endorsed Garcetti for mayor last year.