When I came here I wasn't expecting to win the title at all.
Mona Barthel broke into the world’s top 30 for the first time following her victory at the Open GDF Suez in Paris on Sunday
The German No. 3 took out two seeded players en route to the final before claiming a shock 7-5 7-6(4) victory over world No.7 Sara Errani to claim her first Premier title.
Barthel, who had already seen off fifth seed Roberta Vinci in the second round and third seed Marion Bartoli in the quarter-finals, led 5-2 in the second set but Errrani dug deep to keep the match alive.
The top seed proved a tough nut to crack, but Barthel’s aggressive approach – hitting 53 winners and 50 unforced errors – paid off in the end as she clinched the victory with a booming forehand winner.
Sunday’s victory sees Barthel - whose only previous WTA title came in Hobart last year, when she came through qualifying to win – move up 17 places to No.28 in the world rankings.
"When I came here I wasn't expecting to win the title at all," she said. "I was just taking it round by round, hoping to win the first round, then hoping to win the second round, and so on.
“When I got to the final I knew it would be tough, because Sara had such an amazing year last year and is playing so well - she just doesn't give anything away."
There was some swift redemption for Errani, however, as she tasted victory in the doubles alongside fellow Italian Vinci, the top seeds thrashing Andrea Hlavackova and Liezel Huber 6-1 6-1.
Meanwhile, Maria Kirilenko edged out Sabine Lisicki 5-7 6-1 7-6(1) to win the PTT Pattaya Open title in Thailand.