China citizens hold valid American visas. Do they still need a visa to go to Panama?

The original text of the Panamanian Embassy in the United States, official website, is reproduced as follows:

Anyone who holds a valid passport valid for 3 months and a valid visa from one of the following countries, regardless of their nationality, can enter the Republic of Panama: the United States, the United Kingdom, Canada, Australia or any member state of the European Union, and the visa has been used to enter these countries at least once.

If you have a passport of any country valid for more than 3 months and a valid visa of one of the following countries, and you have entered Panama at least once, you can enter Panama without a visa.