The Briton beat title leader Max Verstappen by 0.438s, but Mercedes has been called to the stewards after Hamilton’s DRS - the part of the rear wing that opens on the straights to boost straight-line speed - was found to open more than is allowed under the technical regulations during post-session scrutineering.
If the stewards find a breach has been committed, Hamilton will be forced to start from pit lane, which will promote championship rival Verstappen to pole for the sprint race.
Hamilton was already facing a difficult weekend thanks to an engine change that was set to dock him five places on the grid for tomorrow’s grand prix, which is formed based on the finishing positions of the sprint race today.
Mercedes’s strong performance in qualifying had given Hamilton cause for optimism before he was called to the stewards. The Briton is attempting to ignite a 19-point fightback in the final four rounds of the season, and this was his first qualifying-topping result since August’s Hungarian Grand Prix.
“A big thankyou to all the team, because they’ve been working flat out,” he said. “Today was a really good qualifying session. I’m super happy with it. We’ll give it everything we’ve got.
“I feel really grateful. It’s crazy, because it’s been a while, so it feels like the first.”
Verstappen was sanguine about being beaten, the Dutchman chalking the bulk of the difference down to Hamilton’s new motor.
“When they take a new engine naturally they have a bit more power for a weekend, so for me it’s not a big shock,” he said. “I’m just happy to be second, it’s a good position to start from.
“Of course you always want to be closer, but sometimes you just have to be more realistic.”
Valtteri Bottas will line up third and more than half a second off the pace, and the Finn is hoping to capitalise on potential action at turn one after losing out at the start of the previous race in Mexico.
“Obviously a good starting place and all to play for, and hopefully it will be lap one full of action, so let’s see,” he said.
Sergio Perez will start fourth for Red Bull Racing.
AlphaTauri’s Pierre Gasly and Ferrari’s Carlos Sainz, podium getters in 2019, were closely matched to line up fifth and sixth for the sprint, with Charles Leclerc taking the second Ferrari to seventh.
McLaren teammates Lando Norris and Daniel Ricciardo were surprised to make it into the top 10, the pair beating Alpine duo Fernando Alonso, knocked out 10th, and Esteban Ocon, who will start 11th after exiting in Q2.
Sebastian Vettel will start today’s sprint race 12th ahead of Yuki Tsunoda for AlphaTauri, the Japanese rookie breaking his three-race streak of top-10 appearances.
Alfa Romeo duo Kimi Raikkonen and Antonio Giovinazzi will start 14th and 15th ahead of Aston Martin’s Lance Stroll.
Williams duo Nicholas Latifi and George Russell qualified 17th and 18th. It was the first time Latifi has beaten Russell in qualifying in their-two year partnership and the first time Russell has been beaten by a Williams teammate in his three-season career.
Haas teammates Mick Schumacher and Nikita Mazepin qualified 19th and 20th.