Italian Camila Giorgi knocked out another seed on her way to clinching a spot in the Merida Open final where she will face Sweden's Rebecca Peterson.

Giorgi triumphed 7-5 7-6 (7-2) over fourth seed Katerina Siniakova in two hours and 12 minutes in Saturday's semi-final in Akron.

The Italian world number 68 had routed second seed Sloane Stephens 6-0 6-0 on Friday to earn her spot in the last four.

Swedish qualifier Peterson secured her final berth with a 6-2 6-7 (4-7) 6-4 over American Caty McNally.

The topsy-turvy match lasted almost three hours, with Peterson fighting back from 4-0 down in the third set by winning the final six games for victory.