Lewis: "Sochi has been one of the weaker circuits for me in the past, particularly last year.
"So I've done a lot of work to understand the balance and see where I can improve to try and rectify this - today has been good in that sense.
"From every race we're learning more and more and particularly the last few races have helped us to really gauge which foot we need to start on for the weekend.
"We've brought more upgrades this weekend; there's so much work going on at home and it's just really encouraging when you come to a race and you get an upgrade, knowing that this late in the season we're also already working on next year's car - it motivates me to get the best out of everything.
"It's been a good day for us, so let's hope that it continues tomorrow."