Mercedes headed into the first day of the 2018 Formula 1 season looking in good shape after a strong showing in pre-season, but today's two free practice sessions had the potential to change everything.

Inevitably, the identity of the pacesetter - Lewis Hamilton - suggests things went as expected but there were some genuine surprises and intriguing patterns on the first day of running.

On top of that, we also learned a little more about which team is best placed to mount a challenge to F1's dominant force of the V6 turbo hybrid era, and had the chance to see how some major upgrade packages impacted the competitive order.