Thiem delights in Stuttgart victory over Federer

Rising star Dominic Thiem described himself as the "happiest person on the earth" after coming from behind to beat Roger Federer in a dramatic, rain-interrupted Stuttgart Open semi-final.

Twenty-two-year-old Thiem, up to a career-high seventh in the ATP world rankings following his run to the semi-finals of the French Open, saved two match points in a second-set tie-break before eventually prevailing 3-6 7-6 (9-7) 6-4 on Saturday.

A thrilling encounter was twice interrupted by showers, at the end of set two - which Thiem had led 5-0 prior to a Federer fightback - and after the Austrian had broken for a 4-3 lead in the decider.

Having beaten seven-time Wimbledon champion Federer, returning this week from the back injury that prevented him from competing at Roland Garros, Thiem will now face Juan Martin del Potro or Philipp Kohlschreiber in Sunday's final.

"I can't believe it. To beat Federer on grass is a dream," the youngster was quoted as saying by the ATP World Tour's official website.

"You need a little bit of luck to beat him on his best surface. I'm the happiest person on the earth now."