The chair umpire awarded the fifth-seeded Errani an ace on her first match point after going down to check the mark on the red clay court and overruling the linesman's call.
"It was a great match for me. Maybe neither of us played our best, but it was very important for me to win today,'' Errani said. "I think the difference between us was I was stronger in the long points. It was difficult to stay physically strong the whole week because it's very hot here, but I think I did better in the end.''
She is the first Italian to win the singles crown in Palermo.
Errani had never been to a tour final of any kind before this week. Now she owns singles and doubles titles. On Saturday, Errani teamed with Nuria Llagostera Vives to capture the doubles crown.
Koryttseva, the No. 7 seed, was also trying for her first WTA title in her second final appearance.
"I was trying my best, but it just wasn't my day,'' Koryttseva said. "She was using smart tactics and I just wasn't able to play my game. I could have won my first title today but I can't think about that - tomorrow is another day and another tournament. I just try to improve my game, day by day.''
Medina Garrigues, Pennetta upset at Palermo
Liverani joins Palermo
Medina Garrigues advances to semifinals in Palermo
