Top seed David Goffin fought back from a set and a break down to beat Victor Estrella Burgos and set up a BMW Open quarter-final against Alexander Zverev on Thursday.
Goffin has been a beaten semi-finalist twice this year, but moved a step closer to reaching his first final of 2016 by seeing off Estrella Burgos 5-7 6-3 6-2 in the round of 16.
The world number 13 was in danger of bowing out in Munich when his unseeded opponent broke to love to lead 3-2 in the second set, but the tide then turned in Goffin's favour.
The Belgian won four games in a row to take the match into a third set and maintained his momentum to claim a further three breaks in the decider and oust the veteran from the Dominican Republic.
Goffin, who sent down 10 aces and saved 10 of 14 break points, will now face Zverev after the promising German teenager sent Lukas Rosol packing.
Zverev, 19, produced an impressive service display and needed just the one break in each set to beat the Czech 6-3 6-4.
Philipp Kohlschreiber was runner-up to Andy Murray last year and remains in contention to win the tournament for a third time on home soil following a 6-3 6-2 triumph over compatriot Florian Mayer.
Kohlschreiber will take on Juan Martin del Potro in the last eight after the Argentine, playing his first tournament on clay for three years, lasted the distance in a 6-2 3-6 6-3 victory against Jan-Lennard Struff.
Del Potro showed signs of nerves as three match points went begging when leading 5-1, but he served out at the second time of asking.
Dominic Thiem, Fabio Fognini and Jozef Kovalik also sealed their places in the quarter-finals.