DOHA, Nov 30 (Reuters) - Carlos Sainz expected Qatar to be his hardest race of the year and ended up celebrating a surprise second podium of the season that secured fifth place in the championship for his resurgent Williams team.

The Spaniard has now taken twice as many top-three placings in 2025 as Lewis Hamilton, the seven-times world champion who replaced him at Ferrari in January and has yet to finish higher than fourth.

"I think it's my proudest day in Williams," he said after finishing third behind Red Bull's race winner Max Verstappen and McLaren's Oscar Piastri.

"Happiest? Maybe Baku, because I was just so happy to get my first podium for the team... I think I feel really proud of everyone. Just very proud of myself, but mainly the whole team for the weekend that we've executed."

The points left the former champions on 137 points and fifth, 45 clear of Racing Bulls, with a maximum 43 still to be won in the final round in Abu Dhabi.

Ferrari are fourth, 245 points ahead, but fifth marks the best season for Williams since 2017. Last year, they ended up ninth with just 17 points.

"I was proud of Carlos and the team when we got our first podium in Baku," said team boss James Vowles.

"The second is a dream come true, but perhaps more importantly at a track that was almost our worst last year. And we've come back, we've reinvented ourselves and the result is there for everyone to see."

(Reporting by Alan Baldwin, editing by Pritha Sarkar)