Rising star Karen Khachanov saved two match points before coming back to beat Ernests Gulbis at the Swedish Open on Thursday.
The young Russian saved match points at 4-5 and 5-6 in the second set before rallying to complete 4-6, 7-6 (7-5), 6-3 victory in two hours and 10 minutes.
Khachanov is currently ranked a career-high 33rd in the world, and is now the leading Russian in the Top 100 of the Emirates ATP Rankings.
He advanced to his fourth ATP World Tour quarter-final, where he will take on Alexandr Dolgopolov, who was a 6-4, 6-4 winner over Horacio Zeballos.
Elsewhere, defending champion Albert Ramos-Vinolas beat Thiago Monteiro 3-6, 6-4, 6-3.
That set up a quarter-final clash with fellow Spaniard Fernando Verdasco in a repeat of last year's Swedish Open final.
Verdasco ousted Argentina's Facundo Bagnis 6-3, 6-2.
Q-finals on Friday:
?? Kuznetsov vs ?? Schwartzman
?? Khachanov vs ?? Dolgopolov
?? Ferrer vs ?? Laaksonen
?? Verdasco vs ?? Ramos-Vinolas pic.twitter.com/LkoMH4stJm
— Swedish Open Tennis (@swedish_open) 20 July 2017