Caleb White had 16, including 10-straight East Carolina points in the first half. Michael Zangari added 11 points and 10 rebounds for the Pirates (3-2).
Fresno State got within 50-48 with 3:13 left, but Tyson made a layup and hit all six of his free throw attempts in the final three minutes to seal it.
Julien Lewis scored 23 points on 8-of-17 shooting for Fresno State (1-4) and Marvelle Harris added 12. The Bulldogs were held to 16-of-49 (32.7 percent) shooting.
Lewis' 3-pointer midway through the first half gave Fresno State a 14-12 lead, but the Bulldogs only made three more field goals by the break and trailed 31-22.
East Carolina will play in the fifth-place game on Wednesday.