Wimbledon champion Venus Williams overpowered fellow American Jill Craybas 6-3, 6-1 to book her spot in the Japan Open second round on Tuesday.
The former world number one, winner of the Korea Open title at the weekend, recovered from an indifferent start on the Tokyo hardcourts, wrapping up the match in just 59 minutes.
"I love to play faster and harder and be aggressive," Williams told reporters after a successful Japan Open debut.
"It's a great surface for me. It excites me"
The 27-year-old finished off Craybas with a ferocious backhand down the line for her 16th victory in 18 matches since claiming her sixth grand slam title at Wimbledon.
Williams immediately expressed confidence that she would qualify for the next month's season-ending WTA Tour Championships, for which only the year's top eight players are eligible.
"That was a definitely a big reason I came here," said Williams, who was a late entry for the Japan Open. "I'm number eight and winning last week made the gap bigger.
"The person behind me (Slovakia's Daniela Hantuchova) is going to have to play really well to pass me."
Maria Kirilenko, beaten by Williams in Sunday's final in Seoul, fell at the first hurdle in Tokyo. The third-seeded Russian lost 6-3, 4-6, 6-3 to Frenchwoman Camille Pin.
Fourth seed Ai Sugiyama was another early loser, upset 6-3, 6-3 by Chinese qualifier Yuan Meng to spoil the Japanese player's 14th appearance in her home event.
The top seeds in the men's draw, blighted by the late withdrawal of world number one Roger Federer, received first round byes.