Ferrer sees off Seppi
Alexander Zverev continued his remarkable run to reach the quarter-finals of the bet-at-home Open in Hamburg, where the top remaining seed David Ferrer was pushed all the way.
The 17-year-old German had not won a match at ATP Tour level before this week but made it three in a row with a 6-4 7-6 (8/6) victory over 11th seed Santiago Giraldo.
Zverev, ranked 285th, is the youngest player to reach the last eight at an ATP Tour 500 tournament since Rafael Nadal in Dubai 10 years ago.
In the quarter-finals, Zverev will meet another Hamburg resident, Tobias Kamke, who upset fourth seed Alexandr Dolgopolov 7-5 2-6 7-5.
David Ferrer is the only one of the top four seeds remaining, and the Spaniard was given a tough time before seeing off Andreas Seppi 6-3 3-6 6-3.
Third seed Tommy Robredo was beaten 7-5 7-6 (8/6) by Lukas Rosol, who next plays German Philipp Kohlschreiber, a 7-5 6-3 winner over Gilles Simon.
Dustin Brown could not make it four Germans through to the quarter-finals, losing 6-1 6-2 to Spain's Pablo Andujar.
Argentina's Leonardo Mayer eased to a 6-3 6-2 win over young Austrian Dominic Thiem, while Dusan Lajovic was leading 3-1 in the battle of the young Serbians against Filip Krajinovic when the latter retired.