Points leader Fabio Leimer set the pace in Friday morning’s free practice for the GP2 Series finale in Abu Dhabi, 0.158 seconds quicker than title rival Sam Bird.
Singapore race winner Jolyon Palmer set the pace in the early stages for Carlin with a 1m52.949s, until Bird hit the track and unleashed a 1m52.381s in his Russian Time entry.
His team-mate Tom Dillmann immediately leapt to second, just a tenth off the fastest time, while Racing Engineering’s Leimer went third fastest on his first run, 0.235s off the leading pace.
Dani Clos then briefly jumped to the top of the times in his MP Motorsport machine, 0.026s ahead of Bird, as Alexander Rossi demoted Dillmann from third, with a lap 0.042s off the benchmark time.
On the second runs, Bird retook top spot with 1m51.924s, but was demoted by Leimer with a 1m51.766s that remained the best time until the end of the half-hour session.
Bird was slightly quicker on his final lap until he aborted it, setting up an intriguing scenario going into qualifying, in which the four points on offer for pole could prove crucial in the final reckoning. Bird is seven behind Leimer at present.
Clos dropped to third, ahead of Rossi.
James Calado, who has the slimmest of title hopes in his ART car, was fifth fastest. However, he is under investigation by the stewards after he tripped over sixth-fastest Dillmann and vented his feelings by running him wide off the track.
Jon Lancaster was seventh fastest, despite a spin. Simon Trummer and Daniel de Jong were also spinners during the session.
Of the other title contenders, Felipe Nasr was 10th and Stefano Coletti, who has been in freefall since the middle of the season, was 23rd and 2.2s off the pace.
All drivers used the white-walled medium compound Pirelli tyres, but will qualify later on Friday on the super-soft.
Pos  Driver               Team                Time       Gap
 1.  Fabio Leimer         Racing Engineering  1m51.766s
 2.  Sam Bird             Russian Time        1m51.924s  +0.158s
 3.  Dani Clos            MP                  1m52.019s  +0.253s
 4.  Alexander Rossi      Caterham            1m52.061s  +0.295s
 5.  James Calado         ART                 1m52.162s  +0.396s
 6.  Tom Dillmann         Russian Time        1m52.175s  +0.409s
 7.  Jon Lancaster        Hilmer              1m52.543s  +0.777s
 8.  Stephane Richelmi    DAMS                1m52.573s  +0.807s
 9.  Johnny Cecotto Jr    Arden               1m52.583s  +0.817s
 10.  Felipe Nasr          Carlin              1m52.697s  +0.931s
 11.  Rene Binder          Lazarus             1m52.709s  +0.943s
 12.  Marcus Ericsson      DAMS                1m52.801s  +1.035s
 13.  Jolyon Palmer        Carlin              1m52.822s  +1.056s
 14.  Nathanael Berthon    Trident             1m52.853s  +1.087s
 15.  Jake Rosenzweig      Addax               1m52.870s  +1.104s
 16.  Julian Leal          Racing Engineering  1m52.973s  +1.207s
 17.  Sergio Canamasas     Caterham            1m53.225s  +1.459s
 18.  Simon Trummer        Rapax               1m53.383s  +1.617s
 19.  Daniel Abt           ART                 1m53.472s  +1.706s
 20.  Rio Haryanto         Addax               1m53.552s  +1.786s
 21.  Adrian Quaife-Hobbs  Hilmer              1m53.638s  +1.872s
 22.  Daniel de Jong       MP                  1m53.750s  +1.984s
 23.  Stefano Coletti      Rapax               1m53.986s  +2.220s
 24.  Vittorio Ghirelli    Lazarus             1m54.435s  +2.669s
 25.  Gianmarco Raimondo   Trident             1m55.291s  +3.525s
 26.  Mitch Evans          Arden               2m00.403s  +8.637s
 
 








