Sergey Sirotkin labelled his final Formula 1 outing with Williams as “painful” after slumping to last at the Abu Dhabi Grand Prix.
Sirotkin struggled for pace through the weekend but managed to beat team-mate Lance Stroll in their battle at the back of the grid.
But while Force India-bound Stroll went on to classify 13th Sirotkin finished as the last of the 15 remaining runners.
“It was really painful,” Sirotkin said. “It wasn’t the best start, then straight away I lost all the ground and I wasn’t in the best position for the next sequence of corners so couldn’t really get it back.
“Then I had a problem with the overheating of the car, so for one-third of the race I had to do massive cooling. It was such a painful race, such a painful stint.
“I was trying my best to cool it down as quickly as I could, but also the cars who were pitting were coming out behind me and I tried to fight.
“I tried to protect the position and at the same time cool the car. It honestly was such a mess, I didn’t enjoy it.
“After everything came back under control, it was too late, I lost so much race time with that. So it has been a very painful race.
“I really wanted to enjoy it and it’s just so painful to finish the season like this so I will need a little time to forget it.”
Sirotkin has relinquished his drive at Williams after the team opted to promote Robert Kubica as team-mate to newly-crowned Formula 2 champion George Russell.