Championship leader Lewis Hamilton said opening practice at the British Grand Prix on Friday had been "quite difficult, but not disastrous" before welcoming Lance Stroll's success in topping the times for Racing Point.
The six-time world champion and his Mercedes team-mate Valtteri Bottas, who have won all three season-opening races this year, had to settle for fifth and third respectively as Stroll set the pace in his controversial 'pink Mercedes' ahead of Alex Albon's Red Bull.
Stroll's performance was a welcome boost to a Racing Point team reeling from seeing fellow driver Sergio Perez sidelined from the race after testing positive for coronavirus.
The two Mercedes men were separated by Ferrari's Charles Leclerc in an unexpectedly mixed-up practice order that gave Hamilton some pleasure.
"It's great to see our competitors are so quick," he said.
"But it will be very different weather and conditions tomorrow."
Hamilton, in imperious form at the last two races, is bidding for a record-increasing seventh home win at Silverstone on Sunday.
However, he conceded it would need some overnight home work to improve the balance of his car for Saturday's qualifying session.
"It has been quite a difficult day," he said.
"It's windy, as it always is here, but that's a good thing and with the wind coming from different directions it was really tricky.
"The balance of my car is not as good as I would like so we have some work to do tonight. We will figure it out so it is not a disaster, but it has been a hard day."
Stroll topped the times and showed the full potential of his team's 2020 car, modelled on the 2019 title-winning Mercedes, as he outpaced Albon, who crashed heavily during the session, by less than a tenth of a second.
Perez had flown home to Mexico by private jet to visit his mother in hospital following the Hungarian Grand Prix and had shown no symptoms.
His replacement Nico Hulkenberg, a former team-mate, was an encouraging seventh fastest after being called up overnight and thrown into action at very short notice.
"It's been a special, crazy and wild 24 hours, but it's all worth it," said the German driver. "The car is massively quicl."
On a very hot day in central England, the air temperature was 35 degrees Celsius and the track 48 as the second session delivered dramatic and unexpected action in front of empty grandstands and campsites.
Stroll clocked a fastest lap in one minute and 27.274 seconds to beat Albon by 0.090 seconds, before the London-born Thai driver crashed heavily at Stowe corner in pursuit of an improved time.
"The rear went quite quickly and I struggled to correct it," said Albon.
"We've definitely made a step as a team. The car feels good and we expected worse to be honest. The car was hooked up straight away. I'm sure the Mercs are hiding quite a lot, but as a car mine feels well balanced."
Behind the leading five, Carlos Sainz was sixth for McLaren ahead of Hulkenberg, Pierre Gasly of Alpha Tauri, Daniel Ricciardo of Renault and Kimi Raikkonen of Alfa Romeo.
Life in the fast lane: Racing Point's Lance Stroll set the fastest time in practice on Friday