Lewis scored the 97th pole position of his F1 career - his ninth of the 2020 season and first at the Autodromo Internacional do Algarve.
Valtteri finished just a tenth of a second behind Lewis, qualifying in P2, helping the team take its ninth front row lockout of the season and 73rd in F1.
Lewis and Valtteri will both start the 2020 Portuguese Grand Prix on the Medium tyre.
Lewis Hamilton: I can't tell you how hard that was today - we've got a great car, but you have to drive the nuts off it to pull out a lap and Valtteri has just been so quick here this weekend! I've been digging and digging and trying to find that extra time. They communicated well with us and gave us the option of what to do at the end - I chose to do three laps to give a chance at beating his time and he chose to do one. I thought that might give me an opportunity and it worked out, getting better and better on the final lap. This is a hardcore circuit, with places where you can't see where you're going because you're just looking at the sky, so there are no references for braking points for example. It's among the most challenging circuits I've been to, especially with this new surface that makes it hard to get the tyres switched on and working on both axles. It's a big thank you to the team for the work this weekend, and to the fans who were able to come out today - it's great to see their flags out there on track.
Valtteri Bottas: That was a strong session for me until the final run. Based on the feeling from Q2, we decided to go for the medium for the last run, then it was a question of one timed lap or three timed laps of fuel in the car. It's always a balance: with one lap, you carry less fuel weight but might have a challenge with the warm-up of the tyre; that's what I went for as it had worked for me in Q2. It has been tricky to get clean laps this weekend and the final one for me was decent but not perfect - that's the challenge of a track and a surface like this. So of course, a little disappointing not to be on pole after topping the times most of the weekend, but I will be fighting for the win from P2 tomorrow.
Toto Wolff: That was a fantastic qualifying session, coming right down to the very final laps in Q3. We gave both drivers the choice of tyre and run length for the last outing in Q3 - they went for the Medium and Valtteri went for one timed lap, Lewis for three. In the end, it came down to just a tenth of a second between them in a great battle, with Lewis taking pole on his final lap and Valtteri running a little wide in the second sector at Turn 8, until which point he had been slightly ahead on the delta time. In any case, it's set for an intriguing battle tomorrow: we don't have too much information on how the tyres will behave, and both our cars will start on the medium compound; Verstappen on the other hand starts on soft, and has a fresh medium tyre for the race, which will give him some different strategy options. It's looking like an exciting Grand Prix, especially with some rain showers in the forecast too.
Andrew Shovlin: Well done to the drivers on securing another front row for the team and to Lewis on a great lap for pole. It was a really tight session where Max clearly had the pace to fight for pole although he didn't seem to be getting laps together as consistently as we were. The session was also pretty hard to read as getting the tyres in the right window wasn't straightforward, nor was it easy to know whether the medium or the soft was ultimately quicker. The changes that we made overnight seemed to take us in the right direction and we'd also added a bit of downforce which has helped balance and grip at the expense of some straight line speed. The big unknown will be the long runs tomorrow. We'd decided to start both cars on the medium tyre as it gives us a bit of flexibility on the strategy and we'd found the soft tyre to be quite fragile on the long run this morning. However, we're expecting it to be cooler, windier and with a risk of rain which makes it hard to predict how things will go. In recent races we've seen Red Bull getting closer and closer to us on pace so the big question in the first stint will be whether we can build any kind of a gap, assuming we're still in front. After that it's a case of understanding how the tyres are behaving in the different conditions and what to do on strategy. There are many more unknowns than normal but that should help keep it interesting.
Check out our Saturday gallery from Portimao, here.