Mercedes’ Valtteri Bottas has topped FP1 in Barcelona today, ahead of both Ferraris.
The Finnish driver traded times with both Vettel and Leclerc, before an oil leak stopped play for him. It caused an engine shutdown (a precautionary measure), which Mercedes are investigating now.
Hamilton seemed to struggle with tyres and ended fourth, half a second adrift of his teammate.
Leclerc was initially ahead of Vettel in the standings, as Vettel caught traffic in the final sector and ran wide, dipping his wheels into the gravel, while clearing a slower car on the outside exiting the long uphill Turn 12 right-hander.
However, after a cool-down lap, Vettel was able to push again and re-established himself as the lead Ferrari on a 1m18.066s.
Red Bull seem to be the mystery at the moment, seemingly with a lack of pace despite upgrades being brought to the race weekend.
Gasly was 1.3s off the leader with Verstappen 0.6s slower than him, although his session ended early with an unknown issue.
The bulk of the session was without incident until Lance Stroll put his Racing Point into the barriers after having a wobble at turn 9. He got out unhurt but the car took some serious damage.