Top seed Fabio Fognini brought German qualifier Jan-Lennard Struff crashing down to earth with a 6-3 6-1 victory on Saturday that sent him through to the Munich Open final where he will meet another qualifier in Martin Klizan.
Slovak Klizan outclassed defending champion Tommy Haas, back from a six-week injury break, in straight sets to keep his sensational run alive.
Clay court specialist Fognini, the world number 15, gave Struff no chance on a cool spring day in Munich.
"I did exactly what I had to do," the Italian, chasing his second title of the year, told reporters. "I did exactly what my coach told me. I do not know if it is Struff's first semi-final but he did it well here this week."
Klizan, ranked 111, was equally dominant against Haas in his 6-3 6-2 win, booking his second career final after beating Fognini in the St Petersburg decider in 2012.
He had also beaten seeds Mikhail Youzhny and Denis Istomin in earlier rounds.
"That was a very bitter day for me," said the 36-year-old Haas, with his shoulder injury flaring up again and slowing down his serve considerably. "I am very disappointed because I had played good tennis in the previous days."