Campos Racing driver Rio Haryanto edged out Williams F1 development driver Alex Lynn in GP2 free practice at Silverstone.
Haryanto topped the timesheets midway through the session with a 1m40.659s, knocking McLaren protege Stoffel Vandoorne – who struggled early in the session – down to second.
DAMS driver Lynn was able to push the Belgian further down the order in the closing stages to finish the session just 0.003s behind Haryanto.
Hilmer Motorsport’s Nick Yelloly enjoyed a strong session to finish fourth despite going off in the closing stages to bring out the yellow flags.
Alexander Rossi finished fifth ahead of Arthur Pic and early pacesetter Pierre Gasly.
Ferrari protege Raffaele Marciello, Sergey Sirotkin and Jordan King rounded out the top 10.
Oliver Rowland had a mixed GP2 debut. The Formula Renault 3.5 championship leader ran off the track on a number of occasions but finished the session ahead of his team-mate Daniel de Jong in 17th.
Fellow Brit Jon Lancaster also struggled to get to grips on his return to GP2. He finished down in 25th following an off-track excursion early on.