Why does this Tamil hit from the 1980s remind me of Portishead?

The song is Idhu Oru Nila Karam from the 1981 crime thriller Tik Tik Tik. https://open.spotify.com/track/77b11rwbKcWzLpYjeXgBtS?si=mnHkuW_JTdKz07B9toN6dQ&utm_source=copy-link

Can someone break down the influences in this song and portishead or otherwise explain why they sound similar? I'm talking about the beat that comes in after about 20 seconds.