The American, who has become only the second female player to complete the Career Golden Slam, blew the Russian away 6-0 6-1 on the All England Club's famous Centre Court.
"I don't feel invincible," the 30-year-old said. "I just feel good about my game. I just practiced so hard, and it was time."
Williams is the first player to complete the Career Golden Slam in both singles and doubles.