British doubles pair Colin Fleming and Jonathan Marray made it into the semi-finals of Power Horse Cup 2013 in Dusseldorf on Thursday.
The top seeds saw off the challenge of fellow Briton Jamie Murray and Australian John Peers 7-5 6-3.
They will take on another Briton in the last four in Dominic Inglot, whose partner is Treat Huey from the Philippines.
In the men's singles in Germany, second seed Tommy Haas is out following a walkover defeat by Finnish sixth seed Jarkko Nieminen.
Juan Monaco, the third seed, is through to the semi-finals following a 6-3 6-4 triumph over Germany's Tobias Kamke.
Elsewhere, Guido Pella, who beat the number one seed Janko Tipsarevic in the previous round, got the better of Viktor Troicki 7-6 (7/5) 7-5 while Igor Sijsling eased past Jan Hajek 6-3 6-1.