Lewis Hamilton revealed that he believed he had been suffering from an engine issue in the final round of qualifying for the Mexican Grand Prix, which had prevented him from getting the most out of his Mercedes.
The team had been performing strongly this weekend, with the high altitude and thin air seemingly benefitting Hamilton and his team mate George Russell to get the most out of the problematic W13.
But having been quickest in the first two rounds of qualifying, Hamilton put pressure on himself by exceeding track limits in his first Q3 run which meant that his first lap time was deleted.
He was also heard complaining to the Mercedes pit wall about power drop outs, and it's this which left him three tenths shy of overhauling Red Bulls Max Verstappen for pole position at the end of the session.
"In terms of the laps they were pretty closely matched. But obviously when the first one is deleted you have to make sure the second is completely clean.
"[There were] some problems with the engine in Q3, but I'm not quite sure what it was," he told Sky Sports F1. "Definitely it felt like there was quite a bit of time left on the table.
"I think there was a bit of time, but it wasn't three tenths [of a second]. Maybe it was a couple," he suggested. "Three tenths is still a huge chunk.
"I think still they [Red Bull] are ahead of us," he admitted. "I don't know where that extra time came from.
"But it's great to be so close to the Red Bull cars after we have been chasing them each weekend this year."
Team principal Toto Wolff and chief race engineer Andrew Shovlin had other ideas about why Hamilton and Russell had lost out to Verstappen
"We had a mega car today in FP3, as we saw from the lap times in that session, but then conditions changed a bit and it really closed up at the front," commented Wolff. "All the way through the session, we couldn't really match Verstappen in the stadium section."
"After the final practice this morning it looked like we might be in the fight for pole; in the end, the gap at the end to Max was a bit bigger than we had hoped for," added Shovlin.
"We were very close on pace to him into the final sector but couldn't quite match him there in the hotter afternoon conditions. Overall, though, we can take encouragement from the way the car is working with the recent updates."
Despite the disappointment of not being able to clinch pole on Saturday, Russell will be be on the front row while Hamilton will start the race from third place with all to play for.
"I'm proud of the team," he continued. "This is the best qualifying we've had all year. It just shows that you can never give up, and that perseverance is the way forward, so a big thank you to everybody here and back at the factory.
"We can still put some pressure on them with strategy tomorrow," he insisted. "We will just keep pushing, and I'm pretty happy starting from P3. It's a long way down to turn 1!"