Madrid, May 10: Dominic Thiem progressed to the Madrid Open semi-final with a stunning comeback victory over Roger Federer at Caja Magica on Friday.
Federer, seeking to reach the final for the first time since his triumph in 2012, appeared in command after winning the first set in just 30 minutes.
However, it was Thiem who forced the issue in the second and he eventually won a frenetic tie-break, in which he saved two match points, to force a decider.
The Austrian, looking to reach the final for the third successive year, then completed the turnaround as Federer faded, a single break all the Barcelona Open champion needed to set up a last-four clash with Novak Djokovic with a 3-6 7-6 (13-11) 6-4 success.
Thiem defeated Rafael Nadal en route to the Barcelona title but the form that inspired that triumph looked to have escaped him as Federer took command.
He surrendered a break in his first service game of the match, sending an off-balance forehand into the tramlines, and never threatened a response in the opener, which saw him land just 56 per cent of his first serves.
However, Federer was forced to save five break points in the second and he was on the backfoot for much of the tie-break, with his profligacy for not taking either of his match points punished as a supreme forehand pass and then an emphatic smash gave Thiem the set.
Thiem carried his momentum into the third, securing the break as Federer could only divert a venomous forehand into the net. A netted backhand from Thiem got Federer back on terms but the world number five's response was immediate.
Federer's ill-advised decision to leave a wonderful forehand handed the initiative back to Thiem, who made no mistake in serving out the match as the Swiss great swept long off the backhand side.