Crowds of police supporters chanted "Chinese traitors!" and profanities at their largely young opponents -- highlighting the ideological fissures running through the finance hub as it experiences its worst political unrest in a generation, Presstv Reported.
Hong Kong saw two record-breaking rallies earlier this month by anti-government protesters opposed to a now-postponed plan to approve extradition to mainland China.
But it has also been rocked by unprecedented clashes.
On 12 June police used tear gas and rubber bullets to clear largely young anti-extradition protesters from around parliament.
The police classified the demonstration as a riot and defended their tactics, but opponents have accused officers of using excessive force and called for an independent inquiry.
Twice in the last two weeks the city's police headquarters has been blockaded by angry crowds.
Sunday's rally -- comprised of a noticeably older demographic, some waving Chinese flags -- was smaller than the huge anti-extradition marches but nonetheless showed that the police and pro-Beijing establishment still had plenty of supporters.
"I can't put up with peoples' behavior towards police," 70-year-old demonstrator Frances Yu told AFP.
A 54-year-old office worker, who gave his surname as Wong, said officers were trying to "maintain order" and that anti-extradition demonstrators had gone too far.
"It's like they went crazy, those who charged, lambasted police... I find it so senseless," he told AFP.
The rally, which heard speeches from pro-Beijing lawmakers and former police brass, passed off without incident.
But as the pro-government supporters headed for home, many turned on small groups of anti-government opponents who have kept a small camp outside the parliament for the last three weeks.
At one of the subway entrances near the rally some half a dozen pro-democracy protesters were hissed and booed by a much larger crowd of police supporters, some of whom shouted profanities. Police and other supporters had to step in to calm tempers.
Others screamed insults at journalists and at pro-democracy protesters camped out at the entrance to parliament.
Much of the protest artwork and posters pinned to the city's parliament walls were also torn down by police supporters as they passed by.
The pro-democracy camp will hold another rally on Monday, with organizers expecting a huge turnout.
The extradition protests were the latest manifestation of growing fears, especially among young Hong Kongers, that China is trampling on the city's unique freedoms and culture -- aided by the pro-Beijing government.
Years of protests calling for Hong Kongers to be able to elect their leaders have won no concessions from Beijing.
But there is also a staunchly nationalist, pro-establishment strain that runs through the city, especially among older generations, who regard pro-democracy protesters with disdain and welcome Beijing's increased control.
Organizers of the pro-police rally told local media some 165,000 people attended while police gave a lower figure of 53,000 at its peak.
On Sunday Zhou Fengsuo, a survivor of Beijing's deadly Tiananmen crackdown, said he was denied entry into Hong Kong on arrival at the airport, posting a picture online of the refusal form he was given by immigration once he landed in Taiwan.