Robin Haase claimed the scalp of second seed Dominic Thiem to reach the quarter-finals of the Gerry Weber Open on Wednesday.
Thiem was beaten by Rafael Nadal in the semi-finals of the French Open and will not be winning his first tournament of the grass-court season after going down 6-3 7-6 (9-7) to the unseeded Haase.
Haase will play at the quarter-final stage in Halle for the first time in his fifth appearance at the tournament, having saved three set points in the second to dump the world number eight out.
The 42nd-ranked Haase was broken just the once in a strong service display and will take on Richard Gasquet in the next round.
Alexander Zverev also only needed the two sets to go through, seeing off Philipp Kohlschreiber 6-3 6-4 in an all-German second-round match.
Zverev served 10 aces and did not face a break point in the match as he looks to better his run to the semi-finals in 's-Hertogenbosch last week.
Next up for Zverev will be Roberto Bautista Agut, who saw off Dustin Brown 6-4 1-6 7-6 (8-6), while Gasquet marched on with a 6-3 6-3 win over Bernard Tomic.