Alize Cornet saved a match point in the process of beating Camila Giorgi 7-6 (7-3) 5-7 7-5 to take the BNP Paribas Katowice Open title.
The fourth-seeded Frenchwoman edged her Italian opponent out in a marathon three-setter which lasted over three hours.
The first set alone lasted 69 minutes as Cornet scraped into the lead after finally taking control of matters during the tie-break.
Giorgi, playing in her first WTA final, showed admirable fight to come back from 3-0 and 5-3 down in the second set to level the match and take it into a decider.
Cornet once again took an early lead in the third set but Giorgi came back again and even had a chance to take the title when Cornet faced a break point while serving at 4-5.
But Cornet managed to hold and then broke to love in the next game, setting her up to serve things out and complete an epic win.
The world No 22 had eliminated top seed and home favourite Agnieszka Radwanska in the semi-finals, clearing the way to the fourth WTA title of her career.
"What a match. It was definitely a huge fight, which is what I expected, and I had to save a match point to win the title, so it feels very special," said Cornet.
"I gave everything I had. I'm so happy I could win here at this beautiful tournament in Katowice."