McLaren have enjoyed their best race of the Formula One season with Lando Norris dominating Oscar Piastri for a one-two in the Miami Grand Prix sprint, but the Australian runner-up then really struggled when they mislaid their pace in qualifying.
After finishing seventh and with rain and storms forecast for Sunday's (Monday AEST) main race in which Mercedes' Kimi Antonelli will again start on pole, Piastri was left admitting after his mixed fortunes that it could well be a race into the unknown.
"If it is wet, that's going to obviously throw in a lot of spanners in the works, because no-one's really driven these cars in the rain, and no-one really knows what they're going to do," warned the Aussie.
Piastri was left trailing by his world champion teammate Norris by a substantial 3.766 seconds in Saturday's 19-lap sprint, suggesting McLaren's upgrades might have transformed their season.
But the team's enthusiasm quickly evaporated once Norris was only fourth in qualifying with Piastri set to start three places behind in the main race, while championship leader Antonelli looks in prime shape to win a third grand prix in a row.
On a day when Max Verstappen also roared back to his qualifying best in the revamped Red Bull by earning a front-row spot ahead of Ferrari's third-placed Charles Leclerc, there was frustration for world champion constructors McLaren with Piastri talking of a "random" qualifying session.
Indeed, Piastri was grateful, with winds gusting, just to sneak into Q2 in 16th place. Told he had safely qualified, he noted dryly to his engineer that "safely is an ambitious word."
"It was just very variable from a lot of things - wind, track, conditions, what the power unit wants to do, so not the smoothest of sessions," Piastri sighed afterwards, while Norris reckoned it had been a bit of a "reality check" for the team after the sprint dominance.
Earlier, Piastri had had to repel a late challenge from third-placed Leclerc in the sprint to gain seven badly needed points in the championship standings.
"Yes, I'm mostly satisfied," he had shrugged, happy to have moved up from third on the grid as McLaren ended Mercedes' early winning run in the first race back since the F1 season had an enforced break caused by the Middle East conflict.
Norris also couldn't hide his delight at recovering that victorious 2025 feeling, picking up eight points for the win, controlling the race with seemingly little trouble from pole as Mercedes were knocked off the podium for the first time in 2026.
Antonelli suffered a bad start from second on the grid, allowing Piastri to burst past him, and after he ended up fourth, he was demoted to sixth after a five-second penalty for exceeding track limits.
After the break following the March 29 Japanese GP, with the races in Bahrain and Saudi Arabia cancelled, it meant the 19-year-old's championship lead had now been reduced.
The youngster's on 75 points, teammate George Russell, who'll start fifth, on 68, Leclerc 55 with Ferrari colleague Lewis Hamilton, sixth on the grid, on 43, Norris on 33 and Piastri 28.
