Thiem claimed the sixth title of his career in a timely boost ahead of the French Open which starts in Paris on Sunday .
Thiem is the world number 15 who stunned Roger Federer at the Rome Masters last week .
Thiem , the world number 15 who stunned Roger Federer at the Rome Masters last week , claimed the sixth title of his career in a timely boost ahead of the French Open which starts in Paris on Sunday .