Pennetta defeated Spanish qualifier Arantxa Parra Santonja 6-2, 6-3 and Errani, seeded fifth, beat Ukrainian Mariya Koryttseva 6-4, 6-4 in a rematch of last year's final.
Last week's Bastad titlist, Maria Jose Martinez Sanchez of Spain, upset third-seeded Frenchwoman Alize Cornet 6-2, 6-2 on Day 2 in Palermo.
Also, No. 6 Russian Ekaterina Makarova defeated American Jill Craybas 6-3, 6-1 and German Anna-Lena Groenefeld beat No. 8 Argentine Gisela Dulko 6-4, 6-1.