Championship leader Kimi Antonelli bounced back from a troubled sprint by storming to pole position for Sunday's Miami Grand Prix.
Antonelli, 19, continued Mercedes' lock on full qualifying poles this season; Lando Norris' sprint pole Friday was the only time its grip has been broken.
It had appeared Mercedes' dominance this season was under threat as its rivals' new packages slashed its advantage, with Norris converting that pole into sprint victory, but Antonelli answered by claiming a third successive pole.
Max Verstappen burst into life amid a difficult start to the season to claim second, 0.166 seconds behind. Charles Leclerc was third for Ferrari and Norris finished fourth.
Antonelli has won the past two races to sit top of the standings ahead of teammate and leading title rival George Russell, and Antonelli again had the edge on his experienced teammate in the searing heat on the streets around Hard Rock Stadium.
Russell will start fifth, finishing almost fourth-tenths off Antonelli's pace, ahead of Lewis Hamilton and Oscar Piastri.
Reigning champion Norris had earlier clinched his first victory this season with a comfortable win in the 19-lap sprint.
Norris crossed the line almost four-tenths clear of teammate Piastri, but Antonelli had a difficult time.
Antonelli and Russell have struggled with their starts this season, but Mercedes had hoped small tweaks had improved its getaways.
But Antonelli dropped from second to fourth, and Mercedes blamed it on a "glitch."
Ferrari's Charles Leclerc then accused Antonelli of being "bad wheel-to-wheel" before Leclerc went over track limits too many times and was hit with a five-second penalty -- dropping him from fourth to sixth.
Former world champion Jenson Button labelled it a "silly mistake" and one that helped Russell, who was promoted to fourth, cut the title lead to seven points.
McLaren, Ferrari and Red Bull have all brought a major upgrade package to Miami, and that has helped them slash the advantage Mercedes has enjoyed so far this season -- with Russell labelling its improvement "daunting."
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Team principal Toto Wolff said Mercedes is "out of sync" on the upgrade front and it's expected to make its own improvements soon in a fierce development race.
Antonelli's pole was therefore a surprise, and it could prove crucial.
"That first lap was really special. He was three or more tenths ahead of the next guy. Spectacular. That made the pole," Wolff told Sky Sports.
Sunday's race has been moved forward to 6 p.m. UK from 9 p.m. due to the threat of thunderstorms.
Antonelli will hope Mercedes has solved its issue off the line, with a resurgent Verstappen on his tail.
Verstappen, the four-time world champion, has suffered a tough start to the season amid bitter unhappiness at the sport's new regulations. He is ninth in the standings.
But Red Bull's significant upgrades have slashed its deficit to the dominant Mercedes, and Verstappen showed his talent to claim a spot on the front row.
