World number one Roger Federer is on course for a 10th Halle Open title after he defeated Matthew Ebden of Australia in straight sets to book his place on the semi-final for a 14th straight time.
Federer, 36, struggled to find his rhythm but he still had enough to beat Ebden 7-6 (7-2) 7-5 in their last eight clash at the tournament in Germany.
The result was his 19th successive victory on grass as well as victory no. 171 on the ATP Tour.
The Swiss tennis legend will now face American qualifier Dennis Kudla in the semis after he earlier saw off Yuichi Sugita of Japan 6-2 7-5 in their quarterfinal clash.
Roger Federer has to win the tournament to retain his world number one spot in the men’s ranking.