Lewis Hamilton trailed Valtteri Bottas in second practice for the British Grand Prix.
Red Bull's Pierre Gasly was the surprise pacesetter in the first running at Silverstone – but Mercedes returned to their all-conquering best later in the day.
Bottas finished just seven hundredths clear of Hamilton, with the Ferrari duo of Charles Leclerc and Sebastian Vettel third and fourth respectively.
Hamilton is bidding to win his home event for a record sixth time – and he appears well placed to do so with Mercedes holding the edge.
The British star had looked set to eclipse Bottas' time before he ran off at Chapel and had to abort his lap.
It was not all plain sailing for Mercedes, however, as Bottas had a spark plug changed, causing him to lose track time.
The Silverstone track is one of the speediest on the calendar, suiting Ferrari's straight-line speed.
His team-mate Carlos Sainz was eighth in the pecking order as McLaren's resurgence continues.
Max Verstappen, who won last time out in Austria, was seventh for Red Bull.
British rookie George Russell ended the day at the foot of the time sheets. Russell was restricted to just 11 laps with a gearbox issue.
Renault's Daniel Ricciardo, meanwhile, stopped at Becketts with an engine failure on a troubling day for the Australian.
