Kohlschreiber has won eight ATP titles on three different surfaces and got off to his final tournament with a win.
Fognini’s game-play is best suited to red clay courts, which is where he has tasted most of his success.
The 20-year-old Canadian continues his impressive run, beating Giron in straight sets to reach the last four. Elsewhere, Rublev also moves into the Halle semifinals.
The 23-year-old Russian ousts Jordan Thompson in straight sets and will next play Philipp Kohlschreiber.