The competition began at noon at Union Square, where a motorized cable car was set up for the contest, and the San Francisco 49ers' Gold Rush cheerleaders pumped up the crowd trying to catch a glimpse of the bell ringing.
An amateur competition started off the event, with three media personalities showing off their skills, accompanying music and even performances to complement their ringing.
Money prizes for the amateurs' efforts went to local charities.
That was followed by the main contest featuring Muni cable car conductors, who each had 30 seconds to warm up and then two minutes to clamor away on the bell in the same conditions they would on a cable car.
The competitors, Ken Lunardi, Leonard Oats, Jorge Lacayo, Joseph Sue, Singh Rai, Ignacio Sandoval and champion Trini Whittaker, had competed in a preliminary round at the end of June, beating out other Muni cable car workers.
A panel of judges, which included 10-time bell-ringing winner and Muni operator Carl Payne, local business owners, police Chief Greg Suhr and fire Chief Joanne Hayes-White, took into account originality and style.
Last year's defending champion, Whittaker, was dressed in uniform as were his six challengers including the 2011 winner Oats.
Before Whittaker jumped onto the car to compete, he told the crowd that in the year of wearing the crown he had to get used to all the attention.
As he skillfully handled the bell, members of the crowd cheered "Go Trini!"
Whittaker dethroned Oats last year in a "ring-off" after the two tied. It was the first tie in the event's history, Muni officials said.
Whittaker made it to the top of the competition again this year.
Mistress of ceremony and comedienne Debi Durst told Whittaker he "got to keep the tiara" to which he responded, "I feel like Lebron James."
Lunardi came in second, followed by Sue.
All three were given trophies.
Whittaker's family, including his wife, two sons and mother, was at Union Square to support him.
His mother said Whittaker grew up on cable cars and rode them to get to his childhood home in North Beach.
His wife said he practices bell ringing at their San Francisco home and that he loves being part of the cable car community.
The contest had live music by the band The Slot Blades, named after the cable cars' emergency braking system and comprised of Muni operators.
One viewer, Potrero Hill resident Susan Marie Johnson, 64, said she loved watching the competition after hearing about it over the years but never coming out to see it in action.
"I love the passion," Johnson said. "These guys are so proud of what they do."