What happened: Fernando Alonso pulled off the circuit in the final sector during the opening segment of Mexico City Grand Prix qualifying. Aston Martin instructed him over the radio to stop the car immediately, prompting race control to wave a red flag in Q1.

Why it matters: The stoppage compounds a difficult Saturday after Alonso suffered a gear failure and loss of power earlier in Mexico City practice. Unable to complete a timed run, the car faces an early qualifying elimination and a back-of-the-grid start.

What to watch: Marshals must clear the track in the stadium section before Q1 can resume for the remainder of the session.