Hingis overpowered seventh-seed Dominique Van Roost of Belgium 6-2, 6-1.
Hingis' next opponent will be Arantxa Sanchez-Vicario, the fourth-seeded Spaniard who beat South Africa's Amanda Coetzer, 6-2, 2-6, 6-3.
Third-seeded Nathalie Tauziat also reached the semifinals, defeating French countrywoman Anne-Gaelle Sidot 7-5, 6-2. Tauziat next faces 17-year-old Belgian Kim Clijsters.
Clijsters, who earlier upset sixth-seeded Anna Kournikova, eliminated No. 2 Conchita Martinez 7-5, 7-5 Friday in a match that saw 15 breaks of serve.
Hingis said her goal is to finish the year ranked No. 1 and believes it helps that other contenders like Venus Williams and Lindsay Davenport played at the Olympics.
"I believe it works for me, because I think a lot of players are tired," said Hingis, who took a month off after her three-set loss to Williams in the U.S. Open semifinals.
Hingis broke Van Roost's serve at 2-0 in the first set after a long game and then rolled to victory with little resistance.
Van Roost, who won a bronze medal in doubles at the Olympics, made it easy for Hingis by making repeated errors.
Hingis will likely pass the idle Williams as the tour's leading money-winner at this event since the she trails the American by $42,000 and is entered in both singles and doubles.
First prize in singles is $89,000.