McLaren says Lando Norris was battling for survival in the closing laps of the French Grand Prix, as a hydraulic failure began to shut his Formula 1 car down.
The problem - a loss of hydraulic pressure - started to set in 20 laps before the finish, at which point Norris was running a comfortable seventh behind team-mate Carlos Sainz Jr.
A number of the car's systems, including the DRS, the brakes, differentials and power steering were affected and Norris fell back into the clutches of the chasing pack.
He lost places to Daniel Ricciardo, Kimi Raikkonen and Nico Hulkenberg on the final lap, although Norris was classified ninth when Ricciardo received a pair of penalties - the first of which was for forcing Norris off-track as the Renault driver overtook him at the chicane.
McLaren team boss Andreas Seidl said there were serious concerns the issue might end Norris's race altogether.
"It was simply about engineers plus Lando trying to survive, which they did," said Seidl.
"They did a great job in battling it through, because it was affecting gear shifting, braking, and power steering.
"Then unfortunately, on the last lap, it was just not enough any more. As soon as Daniel [Ricciardo] was there with the DRS train, we had to give up the positions."
Seidl praised the way in which Norris coped with the situation and maintained pace, despite seeming agitated on the team radio.
"Of course it is normal he gets vocal on the radio, because he needs help from us," added Seidl.
"But again, I think it is simply impressive to see how in this young age, in his eighth race, how he is dealing with that and still could, until the last lap, keep the lap times up."
Explaining how difficult the car was becoming to drive, Norris said its behaviour became "quite unpredictable".
"The braking was really inconsistent," he said.
"Upshifts and downshifts were terrible, the power steering started to go. Then something with the traction and the diff started to go.
"It was a whole load of problems, which weren't very nice to have.
"In the end it cost us P7, so it is frustrating. It would have been nice to have a P6 and P7 for us as a team as I think we deserved it."