Mercedes has ended the opening day’s running in command of proceedings in Silverstone for the 70th Anniversary Grand Prix with Valtteri Bottas and Lewis Hamilton setting the pace.

Bottas proved fastest in the opening 90-minute session before Hamilton led the way in a red flagged second session.

The chequered flag flew early in the afternoon’s session after Antonio Giovinazzi stopped out on track.

The Alfa Romeo rolled to a halt just moments after Sebastian Vettel had been forced off the circuit with a terminal engine issue.

Running early in the day concentrated on the soft compound Pirelli tyres after a step change in rubber compounds over those used last weekend.

Bottas managed a 1:26.166s in the morning, just over a tenth up on Hamilton and 0.7s ahead of Max Verstappen.

It was a similar story in Practice 2, Hamilton setting a 1:25.606s on the medium compound tyres to end the session 0.176s clear of Bottas with Daniel Ricciardo third but more than 0.8s slower than the lead Mercedes.

Ricciardo had been just 17th fastest in opening practice, 2.345s slower than Bottas with a 1:28.511s, the Australian finding 2.1s in the Renault between sessions.

Racing Point’s substitute driver, Nico Hulkenberg, was an impressive fourth and just half a tenth shy of Verstappen’s Practice 1 effort.

That pace was reinforced in the latter session as Lance Stroll and Hulkenberg ended the day in fifth and sixth respectively for the squad.

Verstappen was fourth best in the session, the Red Bull driver finding less than half a second between the two sessions.

His team-mate, Alex Albon, was sixth in the opening session with a 1:27.280s, but fell to 11th later in the day despite finding three tenths of a second.

Also down the order was Vettel, whose 1:27.498s best from FP1 was only marginally slower than the 1:27.198s he mustered later.

He ended the second session just 14th, seven places below where he had been earlier, and stranded on track.

Accelerating out of Luffield in the final minutes of the second session, his car suffered what appeared to be a catastrophic engine failure.

With liquid pouring out the bulging underside of the Ferrari, the German was able to pull the car off the racing line quickly, and off the track entirely at Copse without depositing too much liquid on the road.

It triggered a Full Course Yellow period as the car was recovered, though the session was not stopped.

Moments later, however, Giovinazzi ground to a halt at Becketts, stopping the car on the infield and forcing the red flag to be shown.

With little time left on the clock, which continued to count despite the red flag, it was decided that the session would not restart.

That consigned Giovinazzi to the foot of the timing screens for the session, 2.3s slower than Hamilton at the top end of town.

It was the Italian’s sole session of the day, having made way for Robert Kubica in FP1.

Seventh placed Charles Leclerc was the lead Ferrari at the end of the second practice session from both McLarens and Esteban Ocon for Renault in 10th.

That was a notable improvement for McLaren which had seen Lando Norris in 12th in the opening session and Carlos Sainz in 14th.

Ocon had been 10th fastest in the morning’s running, with Daniil Kvyat ninth for AlphaTauri behind Stroll in eighth and Vettel in seventh.

At the foot of the table was Kevin Magnussen, the Dane four tenths off Kubica’s 1:28.960s who in turn was three tenths away from Kimi Raikkonen.

Practice for the 70th Anniversary Grand Prix continues on Saturday with a final 60-minute session, followed by qualifying at 23:00 AEST.

Result: Formula 1 70th Anniversary Grand Prix, Practice 2

Result: Formula 1 70th Anniversary Grand Prix, Practice 1