Alonso says his Aston Martin is 'too good to be true'
The double Formula One world champion and veteran of 355 races was also fastest in second practice on Friday and Saturday's final session.
The Spaniard, now 41, joined Aston Martin from Renault-owned Alpine at the end of last season when five-times champion Sebastian Vettel retired.
"The whole weekend has been unreal for us," Alonso told reporters after a floodlit qualifying that saw Red Bull sweep the front row, with champion Max Verstappen on pole, and Ferrari fill the second row.
"It was like too good to be true every session and every performance of the car.
"Now there is not much more to downplay anything because this is qualifying, all in the same conditions and we are in the mix with Ferrari and Mercedes. So again, unreal."
Alonso has not won a race for a decade, when he was at Ferrari, and his two titles came with Renault in 2005 and 2006.
His last podium was a third place for Alpine in Qatar in 2021.
"It feels so strange for me to say that we’ll start P5 and maybe we are aiming for more," he said. "Now we’re saying that we start P5 and maybe we fight with the Ferraris for the podium.
"Going for a podium in race one, it feels too good to be true."