British driver Jolyon Palmer finished a frustrating P20 during today's (Friday) opening GP2 practice session in Bahrain after being hampered with brake issues.

Drivers were greeted with scorching air and track temperatures - pushing 40˚C - for the start of the 30-minute session and faced with a very dusty 5.441km track.

On the prime Pirelli tyres, Palmer was running inside the top 10 during the early stages lapping in the mid 1:43s around an unfamiliar track. Yellow flags at Turn 1, following a stop by Tom Dillmann, then disrupted proceedings with Palmer pitting at the halfway stage, suffering from high rear tyre wear.

The 21-year-old then had issues with his brakes and was forced to sit much of the remainder of the session out. With three minutes remaining, he did briefly return to the track but was unable to get a flying lap in.

Speaking afterwards Palmer said: "I set my best lap on my first flying lap whilst I was still learning the circuit. Then we had yellow flags and the rear tyres degraded quite a lot. We did some set up tweaks midway through the session but then I had a problem with the brakes and I didn't get a flying lap afterwards so I ended up P20 with just one flyer under my belt. Qualifying is now going to be harder but no doubt if we can improve the set up we can still fight for the front row places."

DAMS driver Davide Valsecchi finished on top for the session with Max Chilton in second and Addax's Johnny Cecotto in third.

Jolyon is next on track at 14:00 (UK time) for today's qualifying session with full coverage and live timing available on his official website.

GP2 Bahrain, practice results:

1. D Valsecchi, DAMS, 1:41.417s
2. M Chilton, Carlin, +0.671s
3. J Cecotto, Addax, +0.877s
4. F Nasr, DAMS, +0.903s
5. L Razia, Arden, +0.973s
6. F Leimer, Racing, +0.994s
7. E Gutierrez, Lotus GP, +1.232s
8. J Calado, Lotus GP, +1.436s
9. D Clos, Addax, +1.501s
20. J Palmer, iSport, +2.215s