Tipsarevic vanquished wild card entry Ernests Gulbis 6-3, 6-4 and will meet Aliaz Bedene of Slovenia in a Friday quarterfinal match. Germany's Haas beat Canadian-born American Jesse Levin 6-4, 6-2 and and will play Grega Zemlja in the quarters on the indoor hardcourts at Wiener Stadthalle.
Bedene downed American Donald Young 7-6 (7-4), 6-7 (2-7), 6-3 Thursday to advance and Zemlja beat Australian Matthew Ebden 7-5, 6-4.
Marinko Matosevic took out wild card Austrian Dominic Thiem 6-3, 7-6 (7-5) in a second round match and Paoloa Lorenzi beat Canadian qualifier Vasek Pospisil 6-4, 6-4.
Juan Matin del Potro meets Matosevic and Gilles Muller of Luxembourg plays Lorenzi in other quarterfinal matches.
Campus cop fatally shoots Texas student during traffic stop
Sign language interpreter at Mandela service called out as fake on Twitter