Despite a fantastic performance from Valtteri in his 100th F1 race start, he was powerless to hold off Daniel Ricciardo's late charge for the lead and had to settle for a frustrating P2.
"I think the overall feeling is definitely disappointment because we are here to win and we didn't, even though we were leading quite a big part of the race," he admitted afterwards.
"Especially how everything went in the beginning. Then, at the pit stop, the team did a perfect job and I also felt that I maximised the in-lap.
"The pit stop was the quickest we have had for a long time and also the out lap was really good. We were giving everything we had and it kind of felt like we deserved victory... but not today."
Lewis struggled in Qualifying and it was a similar story in the race. But he nonetheless claimed a healthy haul of points with P4.
"We lacked pace from Saturday onwards," he said. "Everything was good on Friday and then the car kind of turned upside down. It was unstable and didn't turn into the corners. There was a lot of performance that we were losing.
"I definitely feel like I was on the top of my game this weekend. I came prepared exactly the same as always. I just struggled with the car and was uncomfortable on Saturday and Sunday. We have to try and figure it out."