Lewis Hamilton and Mercedes teammate Valtteri Bottas were fastest during an incident-packed opening practice for the British Grand Prix on Friday.
Hamilton, who is going for a fifth straight victory and a record sixth overall in his home Formula One race, clocked the best lap time at 0.367 seconds faster than Bottas.
Both drivers hope to bounce back after failing to finish the Austrian GP due to team errors last Sunday in what was Mercedes' worst result since 2016.
Championship leader Sebastian Vettel was third fastest for Ferrari, followed by Australian Daniel Ricciardo for Red Bull, Ferrari's Kimi Raikkonen and Austrian GP winner Max Verstappen, racing for Red Bull.
Vettel leads Hamilton by one point after nine of 21 races thanks to the Briton's misfortune in Austria.
Verstappen had to pull over on the finish straight with a gearbox problem before practice ended, and the Dutch driver wasn't the only one with issues on Silverstone's new asphalt track.
Four-time world champion Hamilton complained: "This track is the bumpiest I've ever been on."
Romain Grosjean spun off at Turn 2 and slid across the gravel trap, slowing the Haas car enough to cushion his impact with the barriers.
"The car is destroyed," said Grosjean, who blamed a bump for keeping his drag reduction system open as he turned.
Raikkonen was next to slide off going around a turn, though the Finn was fortunate to avoid major damage and was able to return with grass-covered tires.
Fernando Alonso also had a big wobble as his McLaren ran wide on Turn 13 but he managed to recover. The Spaniard finished 2.835 seconds slower than Hamilton.
Another practice is scheduled for later Friday, and there will be another on Saturday before qualifying for Sunday's race.
