With a 6-4, 6-2 victory, the 63rd ranked (WTA Tennis) American moves on to the third round of the tournament to face 13th-seeded Simona Halep of Romania on Wednesday.
According to a Sept. 24 AP report, Azarenka was just one of three upsets that took place in the second round at Ariake Colosseum.
Also sent home packing was third-seeded Sara Errani (Italy), ninth-seeded American Sloane Stephens and (No.14) Kirsten Flipkens of Belgium.
For Azarenka, it has been a very tough end of the season, as she was defeated for a second straight year by Serena William at the U.S. Open finals earlier this month.
On Tuesday, she simply couldn't get herself going, as she looked uncomfortable from the opening serve at the Toray Pan Pacific Open 2013 in Tokyo.
Venus capitalized on her opponent's early woes, coming away with three breaks in the first set and two more in the second stanza.
With the victory at Toray Pan Pacific Open 2013 in Tokyo, Venus Williams remains perfect in her career against Azarenka, as she's yet to drop a single set versus the two-time Australian Open champ.