Sonchat, who celebrated the birth of their first baby with wife Jarucha last month, is hoping to wrap up his second title after winning with his brother in Kazan, Russia in January.
The brothers set up a semi-final against Finland’s Harri Heliovaara and Denys Molchanov of Ukraine who moved past India’s Yuki Bhambri and Taiwan’s Ti Chen 6-1 6-2. In the singles second round, Danai lost to former junior world No 1 Bhambri 6-3 4-6 6-2.