Continuing his recent rich vain of form, Bottas lapped the Silverstone circuit in 1:29.106s, to have a 0.078s gap to Lewis Hamilton in second, but a massive 0.498s to Max Verstappen's Red Bull in third, his best time being a 1:29.604s.
Daniel Ricciardo slotted into fourth, just over eight tenths shy of Bottas's benchmark time, with the two Ferrari's surprisingly over a second off the pace.
Kimi Raikkonen was the best placed Ferrari driver in fifth, 1.031s slower than Bottas, with Vettel a further four tenths slower.
Vettel felt dizzy
At the beginning of the opening 90 minutes of practice, Vettel's Ferrari was fitted with the 'shield', the FIA's preferred method of cockpit head protection, slated for introduction as early as next season.
Much like Red Bull's 'Aeroscreen', the device actually a little longer and narrower than the option trailed by that team in Russia last season.
After only completing a single lap with the device attached, Vettel pitted, later commenting that he "felt dizzy" driving the the 'shield' attached. There are more on-track tests slated for later in the season, which will try to solve some of the problems Vettel encountered on his run, in particular, vision.
As attention turned elsewhere, it was soft tyre shod Bottas who smashed the fun and games that Raikkonen and the Red Bull duo were having at the top of the timing sheets, with a 1:30.788s, 1.8s quicker than that trio had managed.
Hamilton then soon got in on the act as well, lowering the time by around three tenths, before Bottas asserted his dominance with the 1:29.106s that would see him unchallenged in P1 for the rest of the session.
There was one big moment in the session, when Vettel spun the Ferrari exiting Chapel, much to the delight of the fans sat in the Becketts grandsstand.
Signs of Progress for McLaren
Positively for the beleaguered McLaren team, Honda's 'Spec 3' engine at least seems to be delivering some power, allowing Alonso and Vandoorne to be competitive. Signs of McLaren progress
The Spanish driver was seventh quickest, but will serve a five place grid penalty for taking a fifth control electronics of the season. They may be more pain to come, as after Second Practice, Honda will evaluate to take a tactical engine penalty.
Belgian Vandoorne was 10th quickest, just 0.042s slower than Massa in a Mercedes powered Williams, which was obviously not at full power, but it is still progress for him and the team.
The other British driver on the grid, Joylon Palmer had a bad start to the weekend, his Renault spending a large chunk of time in the pits, but still managed to complete a healthy number of laps.
Kevin Magnussen gave up his Haas seat for the first time under the Antonio Giovinazzi Friday driver role, the Italian posting 24 laps on his way to 16th quickest, just two places behind temporary team-mate Romain Grosjean.
|3.||Max Verstappen||Red Bull||+0.498s|
|4.||Daniel Ricciardo||Red Bull||+0.836s|
|7.||Danill Kvyat||Toro Rosso||+1.789s|
|11.||Carlos Sainz Jr||Toro Rosso||+2.094s|
|12.||Esteban Ocon||Force India||+2.104s|
|13.||Sergio Perez||Force India||+2.191s|