"I'm here because we've known that there's racism ... around the country forever, but since Trump was elected, it's emboldened them. and we want to show that racists and white supremacists need to crawl back under the rocks from where they were", said Oakland resident Adam Gold, who attended the counterprotest in Ohlone Park.
Mayors in both cities say the two groups invite hate.
He said the group would instead hold a press conference on Saturday in Alamo Square Park.
With the violence in Charlottesville, Virginia, still fresh in everyone's minds, San Francisco police had braced for the worst, fearing the event might attract right-wing extremists.
An Alameda County judge on Friday set bail for 41-year-old Kyle Chapman at $135,000.
The fights led to a handful of arrests in and around Berkeley's Martin Luther King Jr.
Pro-Trump activists called off a "No Marxism in America" rally that was planned for Berkeley's Civic Center Park on Sunday, after police issued strict rules including searches for banned items such as weapons, helmets and even water bottles.
"No tengo miedo", el grito de Barcelona contra el terrorismo
La manifestación, que comenzó a las 18.00 horas locales (16.00 GMT), fue convocada por el Ayuntamiento de Barcelona y el Gobierno regional de Cataluña.
Despite the cancellations, counter-protesters sometimes referred to as "antifa" still showed up where the events were to take place to protest.
"As the week progressed, city leaders took safety measures from us", Berkeley rally co-organizer Gabriel Silva said Saturday.
Despite the fact that rally organizer Amber Cummings had earlier canceled her demonstration, saying she anxious that protesters would attack her supporters, an estimated 4,000 people still showed up in the record heat to voice their opposition to white supremacists and other "alt-right" groups, which accounted for about two dozen in all.
Some people in the crowd outside City Hall on Friday held red, white and blue signs that read "Unite Against Hate".
But after police erected a fence around the park earlier in the day on Saturday to screen people as they entered, Gibson announced the event would be held indoors at a different location. She said she would attend, and asked others not to do so.
An organizer for a right-wing group that had planned a rally in the shadow of the Golden Gate Bridge pleaded for unity while blasting Democratic leaders in San Francisco for stifling his speech.
The infuriatingly dense Gibson, meanwhile, held some kind of press conference in Pacifica Saturday afternoon, and then, as the Chronicle reports, showed up in Crissy Field anyway by late afternoon, flanked by "about 20 would-be rally participants, some of whom said they had come from OR and Washington to attend the aborted rally". According to the Times, Antifa protesters beat one man with a shield and another person wearing an American flag. Lee applauded the counter-protesters who "made sure that the face of love and compassion dominated over hate speech and inciting of violence".
An organizer said she was told on Wednesday by the city manager's office that the permit application failed to include plans for first aid and sanitary services, and that she had failed to provide sufficient identification. The SFGate reported they were quickly swept up by officers inside Civic Center Park.