What happened: Carlos Sainz caught Frederik Vesti navigating Turn 10 during the opening practice session at Autódromo Hermanos Rodríguez. The hold-up interrupted a flying run as Vesti logged Friday development mileage for Mercedes. Both cars continued their scheduled run programs without contact or stoppage.

Why it matters: Track time in opening practice is vital at Mexico City's high altitude, where thin air heavily affects aerodynamic balance and engine cooling. Mercedes entered the weekend balancing reserve evaluations alongside Kimi Antonelli's bid to secure the drivers' title.

What to watch: Teams return to the circuit for Free Practice 2 later Friday to focus on long-run pace and tire degradation.