Wang needed 48 minutes to seal the 6-0 6-0 win over the world number 15, who also suffered first round defeats at the US Open and in Connecticut, Cincinnati and the Canadian Open.
Germany’s seventh-seeded former world number one Angelique Kerber beat last year’s Pan Pacific runner-up Naomi Osaka 6-3 6-4 to avenge her US Open defeat by the Japanese teenager.
Kerber became only the second women’s defending champion to lose in the US Open first round.
“It’s always tough to play against her,” the German told the WTA website after her victory.
“I was trying to come out here and really focus on every single point and make it better than last time... she’s a great player, great, talented player and tough opponent. For sure she will have great success in the future.”
Kerber plays either American qualifier Madison Brengle or Russia’s Daria Kasatkina in the next round.
Local favorite Kurumi Nara beat Kazakh Yulia Putintseva 2-6 6-4 6-2 in another first round contest.