Thiem ended up beating Fernando Verdasco for the first time in a comeback 3-6, 6-3, 6-2 win after the Spaniard had previously won in all four times they have previously played.
The Austrian on home soil as a result is into his 11th Quarter-Final of the season and 49th since 2016 which is best overall on tour.
Rublev also produced an epic victory over Hyeon Chung 6-4, 6-2 avenging his defeat in the 2017 Next Gen ATP Finals. Rublev only faced one break point and as a result, he eased through to the last quarter.
The Russian will now take on Matteo Berrettini in what could be the tie of the Quarter-Finals.
Aljaz Bedene will now take on Gael Monfils in another Quarter-Final after Bedene beat Gilles Simon 6-2, 3-6, 6-3 and for Monfils he gained revenge for a recent defeat to Jannik Sinner with a 6-3, 7-6 win.
Results - Day 6 - Vienna Open 2019
Schwartzman D. (Arg) | 2 | 65 | 6 | 77 | ||||||||
Querrey S. (Usa) | 1 | 77 | 4 | 65 | ||||||||
Carreno-Busta P. (Esp) | 2 | 63 | 6 | 6 | ||||||||
Kukushkin M. (Kaz) | 1 | 77 | 4 | 1 | ||||||||
Chung H. (Kor) | 0 | 4 | 2 | |||||||||
Rublev A. (Rus) | 2 | 6 | 6 | |||||||||
Bedene A. (Slo) | 2 | 6 | 3 | 6 | ||||||||
Simon G. (Fra) | 1 | 2 | 6 | 3 | ||||||||
Thiem D. (Aut) | 2 | 3 | 6 | 6 | ||||||||
Verdasco F. (Esp) | 1 | 6 | 3 | 2 | ||||||||
Sinner J. (ITA) | 0 | 3 | 68 | |||||||||
Monfils G. (Fra) | 2 | 6 | 710 |
Order of Play - Day 7
Berrettini M. (Ita) | - | |||||||||||
Rublev A. (Rus) | - | |||||||||||
Thiem D. (Aut) | - | |||||||||||
Carreno-Busta P. (Esp) | - | |||||||||||
Schwartzman D. (Arg) | - | |||||||||||
Khachanov K. (Rus) | - | |||||||||||
Bedene A. (Slo) | - | |||||||||||
Monfils G. (Fra) | - |