A rally by 25 far-right Proud Boys was crashed by 300 protesters in Manhattan Saturday — and the two groups spent an hour hollering at each other across Fifth Avenue near Trump Tower.

The Proud Boys had planned a rally to voice their opposition to two of their members getting four-year prison sentences last month for pummeling leftist Antifa members during a 2018 brawl on the Upper East Side.

But Antifa members and other Proud Boy opponents found out about the rally plans, and counter-organized a larger shout-fest of their own.

“F–k fascists!” the Antifa side shouted. “Free the boys!” shouted the MAGA-hat-topped Proud Boys.

“The KKK and the Neo-Nazis are being unleashed by Grand Wizard Trump and his Christian-fascist sidekick Pence,” a man in black who stood with the lefty side shouted at one point.

The groups, who were monitored by the NYPD, dispersed without any apparent violence by 3 p.m.

Additional reporting by Laura Italiano