Sergio Perez suggested that a hold-up on pit lane during the final round of qualifying for the Azerbaijan Grand Prix cost him his chance of taking pole position for Sunday's race.
The two Red Bull drivers had topped the times in the first round, and Perez himself was quickest of anyone in Q2 - although his time of 1:41.955s was less than a tenth of a second ahead of Charles Leclerc.
At the start of the final top ten pole shoot-out round it was Leclerc's Ferrari team mate Carlos Sainz who took the early lead, while Perez had a scare as he clipped the wall.
“We were on the limit at times, chasing the lap time massively to try and improve but unfortunately we didn’t manage to make the most out of it.
“When it gets to Q3, run one is when you go balls-out and it was a little bit too much,” he admitted. “I hit the wall a couple of times. Luckily we managed to survive, which is the key here really.”
The Monegasque was subsequently able to put in a sensational final flying lap that no one could match. Leclerc's pole time of 1:41.359s proved to be 0.282s better than Perez' response moments later.
Perez suggested that a hold-up on pit lane before his final run had cost him his chance of taking the top spot, with the team unable to fire up the car in time after a delay refuelling his car after his initial run.
“It was not an ideal qualifying because at the end we just had a problem with the engine, we couldn’t turn it on,” he told the media in parc ferme after the end of qualifying. "We had a little issue with the refueling on my car in Q3.
"I need to speak with the guys," he added in the post-qualifying press conference: "The car wouldn't turn on, so I think there was a miscommunication. We just lost too many seconds, and we got out in a rush as it was tough getting there to make the lap.
"We were out of sequence for our final lap. That meant I was basically on my own and that’s very powerful around here," he added, referring to the advantage of gaining a tow from following in the slip stream of the car ahead.
With his team mate Max Verstappen at the front of the field, Perez had no one to team up with and that meant he lost out on crucial fractions of a second.
"Who knows if it was enough for pole, but certainly we lost a few tenths," he said, while admitting that Leclerc had produced a strong final effort to successfully take pole.
"I think Charles has done a very good lap," he said. "I still think that three tenths was probably too much to find to close the gap to Ferrari."
The Mexican had to settle for second place, putting him on the front row alongside the Ferrari driver for tomorrow's start.
"I am still on the front row," he said. "Anything can happen, especially here. We have both cars in between the Ferraris which is a good thing.
"I think tomorrow is a very long race, so we just have to make sure we are there," he added. "We are going to work as a team to try and get Ferrari, and it would be ideal to get a one-two. We are going to push them hard!"
He added that it would be crucial not to make the same small errors in the race as he had done in Q3: "It's a very long race, at any point you can make a mistake and that's it."