MUNICH (AP) Alexander Zverev of Germany upset top seed David Goffin 6-3, 4-6, 6-3 on Friday to reach the BMW Open semifinals.

The eighth-seeded Zverev fired 10 aces and converted 12 of his 18 break opportunities to prevail over the 13th-ranked Belgian in 2 hours, 22 minutes.

The 19-year-old Zverev - arguably Germany's brightest prospect - next faces the third-seeded Dominic Thiem of Austria, who earlier defeated Ivan Dodig of Croatia 6-4, 4-6, 6-3 at the clay-court tournament.

It will be a fourth semifinal for Zverev, currently ranked a career-best 49th.

Another German, the fourth-seeded Philipp Kohlschreiber, advanced to the other semifinal with a 6-4, 6-1 defeat of wild card Juan Martin del Potro. Kohlschreiber saved both break points he faced and snapped a six-match losing streak against the Argentine.

Kohlschreiber, who is bidding for his third tournament victory, will face Italian fifth-seed Fabio Fognini, who beat lucky loser Jozef Kovalik 6-2, 3-6, 7-5.