Pro-Beijing lawmaker, Junius Ho, was on Wednesday morning stabbed while campaigning in his constituency for the upcoming Hong Kong district council elections.
A video widely circulated online shows the attack on Ho in the far-north town of Tuen Mun.
The footage shows a man handing Ho a bouquet of flowers while asking for a photo together. He then takes out what appears to be a knife from his bag and stabs Ho in the chest.
In the video, you can see the attacker being quickly subdued and held down by a group of bystanders.
A government spokesperson condemned the attack in a statement released later in the day, confirming that a male suspect had been arrested and an in-depth investigation would be conducted.
While being taken away on a stretcher, Ho told reporters that the wound was superficial.
Mr Ho is a controversial figure in Hong Kong, who drew widespread criticism after he was seen shaking hands with groups of men in white t-shirts with alleged links to the organised crime group triads.
The white-shirted men were later captured on video attacking protesters and passengers in Yuen Long MTR station on July 21, which resulted in 45 injuries.
Mr Ho has denied any connections to the triads and the men seen in the videos.
The attack on Ho comes as the British colony turned semi-autonomous Chinese territory remains gripped in five months of political unrest and protests.
Mr Ho is the first pro-Beijing lawmaker campaigning in the current district council elections to be targeted, although pro-democracy candidates and figures have been subject to targeted attacks in the past.