With Shibahara holding serve early in the second set, the five-time major winner dropped just one point and avoided the dreaded “double bagel.”
Swiatek, 23, completed the 6-0 6-1 victory in 65 minutes without seeing a single break point.
Elena Rybakina, the former Wimbledon champion, gave the world number 143 a walkover when she withdrew from her second-round match against Jessika Ponchet of France citing “injuries”.
“I wish I could have completed the remaining Grand Slams of the year in a different manner, but I have to pay attention to my body.”
Ponchet, who defeated Mexico’s Renata Zarazua 6-3 6-3, will now play Caroline Wozniacki, the two-time runner-up.
Jasmine Paolini, the fifth seed from Italy, advanced earlier after Karolina Pliskova withdrew from their second-round match after just three points.
When the 2016 runner-up pulled up hurt in the opening game, she was behind 30 to 15.
