Conditions were incredibly treacherous out on track and were evolving constantly, making it difficult to make the right calls during qualifying.
"This weekend has not been easy at any stage, and this afternoon our entire team really earned their money, from the tyre handlers, to the pit stop crew, the race engineers, strategists and, above all, our two drivers," said Technical Director, James Allison.
"It was a very difficult session, with lightning flashing all around us and changing levels of water not just from run to run, or from session to session, but often during the laps themselves.
"We somehow contrived to always be on track with the right tyre, at the right time and when it came down to the final shootout, with one shot at getting it done, two brilliant laps from Lewis and Valtteri put us on the front row.
"We don't expect tomorrow to be any easier, but we can be very grateful that we didn't stumble when tested this afternoon."