Basel, Switzerland: Stefanos Tsitsipas dominated Peter Gojowczyk 6-3, 6-1 on Thursday to line up a Swiss Indoors quarter-final with one of his toughest NextGen rivals.
The Greek fourth seed will next face Russian Daniil Medvedev, who defeated Italy's Andreas Seppi 7-6 (7/5), 6-2 in their second-round encounter in Basel.
Medvedev owns three titles this season from Sydney, Winston-Salem and last month in Tokyo. He has also defeated last week's Stockholm champion Tsitsipas in two meetings this season, in Miami and the US Open.
Tsitsipas made his trophy breakthrough at the weekend in Sweden with his first career title.
"I'm playing well," said 16th-ranked Tsitsipas, who moved onto 41 victories for the season. "I think the rivalry between the young guys right now maybe even stronger than that of the big names.
"We all want to get to the top sometime, we always want to do better than the other guy."
Tsitsipas, 20, is the youngest player in the ATP Top 20, and the first Greek to win an ATP title. He also reached his first Masters final in Toronto in August before losing to Rafael Nadal.