The game ended with the score 6:2, 6:2.
The meeting lasted 1 hour 9 minutes.
Russian tennis players held the eighth face-to-face meeting.
Medvedev recorded a sixth victory in his asset, two on Rublev's account.
The prize fund of the tournament in the Emirates is about $2.8 million.
Earlier, Medvedev said that a victory over Djokovic would give him confidence in the final of the tournament in Dubai.