Russian tennis player of Armenian descent Karen Khachanov improved to 4-0 in ATP Cup singles, and Russia is now one match win away from reaching the ATP Cup semi-finals unbeaten, the tournament’s official website reveals.

The World No. 17 beat Argentina's Guido Pella 6-2, 7-6(4) on Thursday, January 9 in Sydney, saving five of six break points and controlling play against the left-hander.

The young and powerful Russian squad, led by two 6'6” 23-year-olds – No. 5 Daniil Medvedev and No. 17 Khachanov – dominated Group E play in Perth and have started in similar style at the Final Eight at Ken Rosewall Arena.

Khachanov raced through the opener, breaking three times and dropping only one first-serve point. Pella regrouped in the second set, but the Russian No. 2 clinched it with his sixth ace.

Medvedev will try to push Russia into the semi-finals against Diego Schwartzman. The Russian leads their ATP Head2Head series 2-0, both straight-sets wins.

The winner of Argentina-Russia will face the winner of Argentina-Russia in the semi-finals.