Trevisan, who achieved her first tournament win at the highest level in Rabat last week, worked away a set point in the first set and won 7-6 (10), 7-5. Sasnovitch had previously won in Paris against the grand slam winners Angelique Kerber and Emma Raducanu.
In the quarterfinals, Trevisan will meet Canadian Leylah Fernandez, who faced British teenager Raducanu in the final of the US Open last year. Fernandez defeated American Amanda Anisimova 6-3 4-6 6-3.
Coco Gauff from the United States also reached the quarterfinals, thanks to a win over Belgium’s Elise Mertens: 6-4, 6-0.
