Sebastian Vettel conceded he was not in control for the last 10 laps of his victory at the Bahrain Grand Prix.
The German beat Valtteri Bottas to the win by less than a second after Mercedes appeared to have outsmarted Ferrari at the pit stops.
After seeing the Scuderia give Vettel and team-mate Kimi Raikkonen the soft tyre, Mercedes opted for the longer-lasting medium compound.
Vettel then had to manage his tyres to the finish to avoid making a second stop that would surely have cost him victory.
Despite seeing Bottas grow ever larger in his mirrors over the closing laps, Vettel was able to keep the Finn at bay to claim his second win of the season in his 200th race start.
"I think I came on the radio with 10 laps to go and said I had everything under control. That was a lie! I had nothing under control," he said.
"When they told me the pace of Valtteri at that time, I thought no way I could do that. I was doing the maths in the car and thought he was going to catch me.
"I tried to keep it as clean as possible. Both Mercedes were strong at the end of the first stint and going onto the prime they saw what we did and I thought that was check mate as we have to come in again.
"Then we diverted and I tried to nurse the tyres as much as I could. It worked, but just. Fortunately, Valtteri ran out of laps."
Commenting on the battle that provided the climax to a thrilling race, Bottas added: "I knew there would be a chance that he would struggle in the end.
"I was trying to get every lap and corner perfect to catch him but it was just not quite enough.
"Being second with such a close margin and having such good pace at the end is extremely disappointing. We will try to get them next time."