Bottas heads Hamilton in Mexico

F1 Grand Prix, GP Mexico, Autódromo Hermanos Rodriguez

Valtteri Bottas topped Mercedes team mate Lewis Hamilton as running commenced in Mexico, ahead of Sunday's Mexican Grand Prix. The 90 minutes practice session unusually saw Mercedes use the softest compound tyre, contrary to rivals Ferrari and Red Bull Racing.

The deficit of both Red Bulls was small enough to realistically expect another closely fought weekend. In fact, their deficit to Bottas is about the same, or less than the prediced delta between Pirelli's ultrasoft and supersoft tyres.

Ferrari was slightly further behind, but even then, still fairly comfortably 5th and 6th fastest. Home racer Sergio Perez ended up 7th fastest, 3 tenths behind the slowest Ferrari, and a tenth faster than McLaren's Fernando Alonso. Felipe Massa was 9th, followed by Nico Hulkenberg.

Meanwhile, there were troubles for Alfonso Celis. The Force India driver made it an early end to his session as he crashed his car at Turn 16, breaking off the rear wing of his car as he slid backwards into the barriers.

McLaren's Stoffel Vandoorne didn't even get that far, as he failed to record a laptime. Fitted with a new Honda engine, the Belgian soon encountered more trouble and was forced back to the pits, where the team eventually decided to revert him back to Honda spec 3.7