Sergio Perez revealed he nearly had to retire his Red Bull car before he could win the Azerbaijan Grand Prix.
Perez claimed a dramatic victory in a race which involved a late red flag after his Red Bull teammate crashed out with four laps remaining.
That effectively meant the race would be a two-lap sprint to the finish from a standing start on the grid. Lewis Hamilton beat Perez off the line but went straight on at Turn 1 with overheated brakes.
Perez made it to the finish in front, claiming the second victory of his career and first for Red Bull.
He immediately brought the car to a stop just after the pit exit at Turn 1 and later said he had worried about not finishing.
"First of all I have to say I'm very sorry for Max because he did a tremendous race, and he really deserved that the win," Perez said after the race.
"It would have been incredible to get that one-two for the team. But at the end, you know it is a fantastic day for us.
"We were close to retiring the car, but luckily we managed to finish the race. And really, it was quite difficult all the way until the end."
Red Bull boss Christian Horner later confirmed the team had been dealing with a hydraulics issue.
"He'd been losing [hydraulic pressure] gradually for the second half of the race," Horner said.
"It was a concern at the restart. That's why we restarted his engine so late, to put as little pressure on the system as possible".