This time, the big guys came out to honor the little ones.

Billionaire investor Warren Buffett, Goldman Sachs CEO Lloyd Blankfein and Chicago Mayor Rahm Emanuel congratulated the 37 graduates of the inaugural Chicago class of Goldman Sachs’s 10,000 Small Businesses initiative on Tuesday, the Chicago Tribune reports.

The program, launched in 2009, offers a sort of mini-MBA to entrepreneurs. Over the span of 20 weeks, Chicago small business owners attended 10 eight-hour classes aimed at helping them develop their enterprises.

Chicago is one of seven U.S. cities offering the program. Companies hoping to participate in the initiative must have been in operation for at least two years and have at least $150,000 in yearly revenue and four employees.

Among the Chicago graduates Tuesday was John Griffin, owner of Chicago-based security firm AGB Investigative Services Incorporated, who says his company has already experienced sizable growth since he began the program at the start of 2012. “I’ve been able to negotiate for better margins for my contracts,” Griffin says.

AGB–whose services include everything from cyber security to armed personal guards–expects to increase gross revenue by 35% in 2012. The company has already hired 17 new employees so far this year.

According to a Goldman spokesperson, small business owners consistently say the program’s negotiation lessons are among the most helpful modules. Many small business owners leave money on the table because they don’t set a firm goal, break-even number, or walk-away number before entering a negotiation, the spokesperson says.

Dennis Deer, owner of Deer Rehabilitation Services, also graduated on Tuesday and was elected by his classmates to give a speech introducing Buffett. Like Griffin, Deer had owned and operated his business for nearly 10 years before enrolling the initiative. Despite his years of experience as a small business owner, Deer says the classes have him insight he never received as a hands-on entrepreneur.

“One of the reasons I needed a class was that I had been working in the business, but not working on my business,” Deer says. “I’m a psychologist. I never had any formal business education. … The single most important thing I learned was to be step back, allow my staff to do their jobs, and to focus more on the vision and mission of the company.”