Alexander Bublik beat fellow Kazakhstani Alexander Shevchenko to progress to the quarter-finals at the Swiss Open Gstaad.
Bublik won 6-2 6-3 in 62 minutes to set up a last-eight clash against Argentina’s Francisco Comesana on the clay surface.
After holding serve in the opening game, Bublik immediately broke Shevchenko on his way to a 3-0 lead in the first. He then broke Shevchenko again to clinch the set inside 30 minutes.
Shevchenko started the second on the front foot, breaking Bublik’s first service game, but he was broken twice again before Bublik secured the win with his first match point.
Bublik admitted it was a difficult match, not only because of the conditions, but also due to facing his Davis Cup team-mate.
"It's a beautiful place, but not the easiest conditions to play tennis," said Bublik.
"The ball is flying a bit, so I’m really happy that I came here earlier, last Saturday, to prepare.
"It was not an easy match mentally. I played a compatriot, a guy I share a Davis Cup team with, so I was a bit nervous, but I stayed in the game and used my chances. I'm really happy with that."
Data Debrief: Bublik's rise continues
Despite a first-round exit at Wimbledon, Bublik continues to show his quality on different surfaces.
He is now 14-5 since the Madrid Open in April. Since then, he has won the Halle Open on grass and reached the last eight at Roland-Garros.
His performances have seen him move up to 34th in the ATP rankings after being world number 82 as recently as March.
