Karatsev lives in Moscow so has done what Andrey Rublev and Karen Khachanov the other standout names failed to do in their home tournament.
The second seed did not drop a set en route to the title as he continues his run to the ATP Finals, he currently sits 13th, 675 points behind Hubert Hurkacz.
It continues his breakthrough season which has seen a semi-final at the Australian Open as well as winning in Dubai. He also reached the final in Belgrade.
In the tie, he broke Cilic in the first game and from there did not face a break point and dropping just one point on his first serve to move in front.
He made it even more emphatic in the second set breaking twice before securing his victory on serve.