Russia's Karen Khachanov has claimed his second Australian scalp in as many matches beating John Millman in the quarter-finals of the Kremlin Cup in Moscow.

The Aussie No.3 battled hard for nearly two-and-a-half hours, saving three match points, before losing 7-5, 7-6 (7-4) on Friday.

Khachanov, winner of this event in 2018, had beaten James Duckworth, Australia's No.2, in the quarter-final.

He will now face compatriot Aslan Karatsev who defeated Gilles Simon, of Belgium, 6-4, 6-3.

Lucky loser Ricardas Berankis moved into the last four when the Lithuanian upset Adrian Mannarino 6-2, 7-6 (7-1).

The French veteran had dethroned defending champion Andrey Rublev in the quarter-final and was aiming to reach a third successive final in Moscow. However, he was unable to back that performance up against the world No.108.

Berankis will now meet Marin Cilic, who beat Pedro Martinez, of Spain, 6-1, 6-2.

Cilic, a two-time winner of the event, took only 62 minutes to wrap up victory.