"We could see the start of blisters and he was able to manage that".
"There's a very small lap time gain in having it open just through Turn 1", Hartley said. 'I hope it will be like that for the rest of the year.
That was still slower than Hamilton's morning time of 1:27.487, however, with Vettel third then and half a second slower.
Hamilton, who is going for a fifth straight victory and a record sixth overall in his home Formula One race, clocked the best lap time at 0.367 seconds faster than Bottas.
Donning the red white and blue, will Hamilton strike gold this weekend at Silverstone?
With this result, Sebastian Vettel has retaken the lead of the World Drivers' Championship from Lewis Hamilton with a single point separating the two.
Lewis Hamilton says it's impossible to say how the F1 season will pan out; especially in a season where both Mercedes and Ferrari have at times appeared dominant while other times have been way off the pace. The good is that the weather is fantastic and the crowd was awesome today.
Roger Federer's outfit sets tongues wagging at Wimbledon
Swiss tennis legend Roger Federer is still looking for a new shoe contract but says he has had interest from former sponsor Nike . Sports news site ESPN reported the price tag of Federer's new deal, but Uniqlo has not shared the specific terms.
"The track is the fastest it has ever been; we're flat out through Copse, and Turn One and through Turn Two with the DRS - it's insane how fast it is".
Although Red Bull was able to get the vehicle back to the garage with more than 50 minutes of the session remaining, the scale of the damage ensured Verstappen didn't return to the track.
Mercedes's chief strategist James Vowles came on the radio as the bearer of bad news, admitting his error as Hamilton struggled to comprehend what the team had done.
"However, it is also the bumpiest track I've ever experienced; it's like the Nordschleife!" "Immediately after the race, as soon as they got the auto back, I think that evening there was a fix that... That would be very good news". He did it in his first race for us in Barcelona, if you remember.
Vettel said he was hoping England would progress beyond their World Cup quarter-final match with Belgium, which starts as qualifying finishes at 15:00 BST on Saturday.
"With the speeds we're going now and the G forces we're pulling, I think it's going to be the most physical race of the year".
"I just have the feeling that this is a hugely significant session" - David Croft. Hamilton joked. "I want to watch the game".
"Obviously, we know it was a hard weekend and of course we would have all hoped, wished that it wasn't the way it was but what doesn't kill you only makes you stronger and honestly the spirit within the team is stronger than it has ever been", continued Hamilton.