After just four days in theaters, The Mermaid has grossed an estimated RMB 1 billion ($152.4 million), the biggest four-day start on record, and, what with three days left in the “Golden Week” holiday plus solid word of mouth, it could challenge Monster Hunt ($381 million) to become the highest-grossing film of all-time in China.

Behind The Mermaid, two other homegrown New Year films pics have fared impressively in their own right — From Vegas to Macau III, starring Chow Yun Fat, with an estimated four-day total of RMB 524 million ($79.7 million), and the FX-driven fantasy film The Monkey King 2, which took in with RMB 485 million ($73.8 million). But these both lack the positive word of mouth online driving The Mermaid’s unprecedented success.

Ticket sales during the first four days of the Lunar New Year reached a combined estimated RMB 2.1 billion ($320 million), resulting in the four biggest single days ever at China’s box office.

Valentine’s Day (情人节), another peak moviegoing day for young Chinese couples, will fall on the last day of the public holiday, meaning the entire weeklong holiday has a good chance of hitting RMB 3 billion, a 65% increase over last year’s Lunar New Year period.

Three love-bitten films debut on Sunday — the romantic-comedy Mr. Highheels (高跟鞋先生), distributed by Le Vision Pictures, Love Actually-esque Run For Love (奔爱), starring Zhang Ziyi and Eddie Peng, and distributed by Enlight Media, and Hong Kong director Fruit Chan’s crime thriller Kill Time (谋杀似水年华) from Wanda’s distribution arm Wuzhou Film Distribution.

According to online ticketing portal Maoyan (猫眼), early estimates for screen distribution on Sunday put the three new Valentine’s Day releases behind the three Lunar New Year releases. The Mermaid, still in high demand and with romantic elements to attract V-day couples, will remain unscathed, but screen numbers will drop for From Vegas to Macau III, The Monkey King 2, and holdover Kung Fu Panda 3 (currently at $116.4 million).

Follow Jonathan Papish on Twitter @ChinaBoxOffice