Ferrari junior Mick Schumacher was fastest in practice ahead of the second successive Formula 2 weekend at Silverstone.
Prema's Schumacher topped an F2 practice session for the first time with a 1m39.783s, after last weekend's feature race winner Nikita Mazepin had his fastest lap time deleted for track limits abuse.
Hitech Grand Prix's Mazepin was fastest in all three sectors to briefly displace Schumacher at the top of the timesheets, but Mazepin lost his benchmark a few moments later for running wide at Stowe and dropped to 13th place.
The red flag was then brought out to recover reigning Euroformula Open champion Marino Sato's stricken car after smoke and fire billowed out of the rear of the Trident-run car.
The session restarted with just over 10 minutes of the session remaining, but nobody troubled Schumacher's best effort.
It provides a much-needed boost for single-seater behemoth Prema, who earned just two points last weekend at the same circuit.
Haas F1 reserve driver Louis Deletraz was second-quickest for Charouz Racing System, just 0.031s adrift of Schumacher's best effort.
DAMS' Dan Ticktum, who earned his maiden F2 win last Sunday, completed the top three ahead of championship leader Robert Shwartzman (Prema).
Ticktum's team-mate Sean Gelael was surprise fifth-fastest ahead of Red Bull Honda protege Yuki Tsunoda, who topped practice last weekend.
Williams junior Jack Aitken was seventh for Campos Racing but spun in the dying moments of the session on the exit of Brooklands.
Tsunoda's Carlin team-mate Jehan Daruvala finished the 45-minute session in eighth place ahead of Renault juniors Guanyu Zhou (Virtuosi) and Christian Lundgaard (ART Grand Prix).
Ferrari junior Callum Ilott was 11th ahead of series veteran Luca Ghiotto and his demoted team-mate Mazepin.
ART GP's Marcus Armstrong - one of five Ferrari juniors in the field - continued to struggle at Silverstone, posting the 14th fastest time.
Fellow Ferrari junior Giuliano Alesi spun his HWA Racelab machine on the exit of Brooklands early in the session, but re-joined to post the 18th fastest time.
Earlier on Friday, Trident's David Beckmann topped the FIA Formula 3 practice session ahead of Red Bull junior Jack Doohan (HWA Racelab), who sits 27th in the drivers' championship without a point.
Championship leader Oscar Piastri managed just three laps in the session before the Renault junior was forced to stop his Prema-run car on the exit of Becketts.
Silverstone F2 practice results
|1||Mick Schumacher||Prema Racing||1m39.783s|
|2||Louis Deletraz||Charouz Racing System||0.031s|
|4||Robert Shwartzman||Prema Racing||0.261s|
|7||Jack Aitken||Campos Racing||0.469s|
|10||Christian Lundgaard||ART Grand Prix||0.527s|
|12||Luca Ghiotto||Hitech Grand Prix||0.567s|
|13||Nikita Mazepin||Hitech Grand Prix||0.587s|
|14||Marcus Armstrong||ART Grand Prix||0.709s|
|15||Pedro Piquet||Charouz Racing System||0.816s|
|16||Nobuharu Matsushita||MP Motorsport||0.863s|
|17||Felipe Drugovich||MP Motorsport||1.272s|
|18||Giuliano Alesi||BWT HWA RACELAB||1.513s|
|20||Artem Markelov||BWT HWA RACELAB||1.768s|
|22||Guilherme Samaia||Campos Racing||2.933s|