A brace by Dynamo winger Alexander Tashaev heaped more misery on CSKA who warmed up for the visit of Arsenal in midweek with a 2-1 derby defeat on Monday.

Already reeling from their 4-1 thrashing in London last week in their Europa League quarter-final first leg, CSKA's season is rapidly unravelling as they remain eight points off Russian Premier League leaders Lokomotiv Moscow, and on the brink of a European exit.

Victory lifted resurgent Dynamo -- newly promoted this season -- up to 10th after struggling earlie in the season.

"The result is logical as we made too many mistakes," CSKA coach Viktor Gancharenko said of his side's error-strewn performance.

"Dynamo looked more focused, more energetic in the first half, and that was decisive. After the break we made some changes and scored a goal but it wasn't enough."

Dynamo opened the scoring on 11 minutes as Tashaev beat goalkeeper Igor Akinfeev with a low, angled shot.

He doubled Dynamo's advantage four minutes after the interval, tapping home Yevgeny Lutsenko's left-wing cross from close range.

Spurred on by a 20,000 home crowd, CSKA poured forward and substitute Fedor Chalov reduced the arrears after the hour mark.

"CSKA gave us a lot of free space in the first half and we capitalised on that," Dynamo head coach Dmitry Khokhlov said.

"They increased the pressure after the break but luckily we managed to hold onto our lead."

With just six matches remaining, CSKA's title hopes look grim while it would take something special to turn around their quarter-final second leg on Thursday.