Basel, Switzerland, 26 October 2018 | Reuters

Australian qualifier Alexei Popyrin has been knocked out of the Swiss Indoors with opponent Alexander Zverev progressing to the quarterfinals.

The second-seeded German beat Popyrin 6-4 6-4 in their second round match at the St. Jakobshalle in Basel on Thursday to secure his 51st win of the season.

German Zverev, who is chasing a fourth ATP title this season, lost only two first-serve points on the way to victory.

Zverev was impressed by the Sydney-born 19-year-old, who recorded his first ATP main draw victory in the first round against compatriot Matthew Ebden.

“He has a very good technique, I think he’s going to be very dangerous in the coming years,” said 21-year-old Zverev.

“He has tremendous talent and tremendous potential. He’s going to be a very good player in the future. He wasn’t nervous, he enjoyed his time out there.”

Zverev next faces Roberto Bautista Agut.