Charles Leclerc led the way for Ferrari in a very tight final practice session at the British Grand Prix.
Light rain early meant running was limited to a few laps on intermediates before the drivers switched back to slicks.
In the first series of soft tyre runs, the order changed consistently as conditions improved with Hamilton holding a one-tenth advantage over Mercedes teammate Valtteri Bottas.
The two Red Bulls followed right behind ahead of the two Ferraris, with Gasly continuing his much-improved form from Friday.
Daniel Ricciardo would lead the midfield in seventh but only just ahead of the two McLarens, who were using the medium compound for their initial flying laps.
After a quick change of tyres, Leclerc charged to the top of the timesheet with a 1m25.905s, 0.026s ahead of teammate Vettel, who set his best time on the second flying lap.
Hamilton dropped to third but would gradually close the gap to finish only half a tenth back of the Monegasque in third, setting up a very close fight for qualifying.
Pierre Gasly’s strong weekend continued in fourth, three-tenths ahead of teammate Max Verstappen as Red Bull also put themselves within striking distance.
Valtteri Bottas is the unknown quantity, however, with his second series of laps compromised by traffic and small errors, leaving the Finn down in sixth.
Lando Norris remained the lead midfield driver in seventh for McLaren, finishing less than 0.8s off the pace set by Leclerc.
Renault has brought themselves into play, however, as Nico Hulkenberg and Daniel Ricciardo sat just 0.02s apart in eighth and ninth.
Also quietly impressing this weekend is Alex Albon in the Toro Rosso, who made it three top 10s in the practice sessions for Toro Rosso in P10.
Antonio Giovinazzi’s increased confidence from Austria was on show as he claimed P11, four-tenths clear of Alfa Romeo teammate Kimi Raikkonen in 16th.
Carlos Sainz has work to do, however, to catch his McLaren teammate as the Spaniard was a disappointing 12th.
Haas showed some progression with Romain Grosjean ahead of Kevin Magnussen in 14th and 15th respectively.
The two Racing Points look set for an early Q1 exit without a decent improvement in qualifying though, as Lance Stroll would be marginally faster than teammate Sergio Perez with the Canadian trying to avoid a 13th straight early elimination.
Finally, Williams continues to bring up the rear with George Russell a massive 1.5s slower than Perez in 19th, but still four-tenths up on Robert Kubica.
With further rain possible almost anything could happen in the fight for pole, but right now a thrilling battle is very much on the cards at Silverstone.
Full results from Practice 3 can be seen below:
