Alessio Picariello led the way in the second and final MRF Challenge practice at the Dubai Autodrome, keeping championship leader Pietro Fittipaldi at bay.
The Belgian clocked a time of 2m00.337s, which was only 0.062s quicker than Fittipaldi's best lap, to sweep the practice sessions.
Championship contenders Tatiana Calderon and Nikita Troitskiy finished third and fourth, the Colombian edging the Russian on her last lap after the chequered flag was waved.
Jean Alesi's son Giuliano continued his fine run, finishing fifth, while Sean Walkinshaw was sixth, the last driver within the second of the leader.
Walkinshaw was followed by fellow Brits Max Fewtrell and Harrison Newey.
Australian Dylan Young finished ninth and Indian Tarun Reddy rounded off the top 10. Newcomers Rik Breukers and Jose Abadin were 11th and 12th.
Arjun Narendran will have a engine change before the qualifying as he is stalling in fourth gear.