The dance video to "Gentleman", the South Korean singer's long-awaited follow up to "Gangnam Style, was only posted on YouTube at 9:00 pm (1200 GMT) on Saturday.
In the first 24 hours, it racked up around 20 million hits, destroying the previous record for single-day views of 8.0 million, set by Canadian heartthrob Justin Bieber's "Boyfriend" video in May 2012.
Now that record looks set to be stretched again, with the view count about 40 hours after release standing at 51 million.
"51million views in 40hours!! My God!!!" the 35-year-old star exclaimed on his Twitter account.
The video shows Psy, wearing his signature sunglasses, dancing at various locations in and around Seoul including a high-end clothing store, restaurant, swimming pool and a library.
The storyline features the singer teasing and playing practical jokes on women, such as pulling their chairs away as they are about to sit or untying a woman's bikini top at a swimming pool, before meeting his match.
It was the video of "Gangnam Style", and in particular Psy's signature horse-riding dance, that pushed him to global stardom last year after it was posted on YouTube and turned into a viral sensation.
A satire on the luxury lifestyle of Seoul's upscale Gangnam district, it has become the most-watched YouTube video of all time, registering more than 1.5 billion views since it debuted last July.
"Gentleman" was ranked in the top 10 songs on iTunes stores in a number of countries Monday, including France, Canada, New Zealand, Denmark and Sweden. It also topped the chart in Finland.
Critical reactions to the song were mixed but the video showing the quirky singer's signature self-mocking humour as well as the new hip-swivelling dance left many fans satisfied.
"The song isn't all that great but let's face it. The video is actually hilarious," wrote one Youtube commentator.
"I just love the fact that neither he nor the dancers are taking themselves too serious, but seriously enough to pelvic sway with perfect synchronization," wrote another.