Ferrari's Sebastian Vettel topped the opening test of 2016 by over half a second as reigning world champion Lewis Hamilton completed two race distances in one day.
Vettel's Ferrari went top early on in the session with a 1:24.939, which finished the day 0.470s up on Hamilton in second -- both times set on Pirelli's medium tyre. The Ferrari driver covered 69 laps in the day.
However, arguably even more impressive was Hamilton's lap count, with 156 laps to his name by the end of the session, 68 more than the nearest car. Mercedes' high mileage count has parallels with 2015's opening test, when Nico Rosberg posted 157 laps -- 84 more than his nearest rival -- at Jerez.
Romain Grosjean and F1 debutants Haas had a mixed first day of testing, with the team's morning running curtailed by a front wing failure with just 13 laps to his name, which triggered the only red flag of the session. Though Grosjean managed to avoid a serious accident the investigation into the failure kept Haas in the garage until 1650 when he emerged again, ending the day in tenth with 31 laps completed.
Red Bull's Daniel Ricciardo finished third, 1.105s off former team-mate Vettel as Red Bull completed 87 laps with its TAG Heuer-branded engine in a day which seemed to pass without incident. Williams driver Valtteri Bottas finished just 0.05s behind in a solid but unspectacular first day for Williams which saw him accumulate 80 laps.
Force India development driver Alfonso Celis jumped into fifth with a late soft tyre run as Force India finished fifth in the newly-unveiled VJM09. Behind was Jenson Button, who registered a positive day for McLaren, finishing sixth and surpassing a race distance with 84 laps. His final time was set on the soft tyres in the final hour of the session, leaving him sixth when the chequered flag fell.
Toro Rosso, decked out in a plain blue livery, ticked off 55 laps with Carlos Sainz while Marcus Ericsson completed the second-highest amount of laps behind Hamilton with 88 to his name in the 2015-spec Sauber. The team plans to bring its 2016 car to the second test, which begins next week.
After its new car broke cover for the first time, Manor's Wehrlein finished in ninth after completing 54 laps. With a new supply of Mercedes engines the team will expect to move up the grid after being perennial backmarkers in its tenure in F1 so far.
The first day did not run smoothly for Renault, which finished the first day over four seconds off the pace and with just 37 laps completed by rookie Jolyon Palmer. The team has already admitted a compromise in development from its late purchase of Lotus and the opening day of testing suggests the team is starting on the back foot.
Times:
1. Sebastian Vettel - Ferrari - 1:24.939 - 69 laps
2. Lewis Hamilton - Mercedes - 1:25.409 - 156 laps
3. Daniel Ricciardo - Red Bull - 1:26.044 - 87 laps
4. Valtteri Bottas - Williams - 1:26.091 - 80 laps
5. Alfonso Celis - Force India - 1:26.298 - 58 laps
6. Jenson Button - McLaren - 1:26.735 - 84 laps
7. Carlos Sainz - Toro Rosso 1.27.180 - 55 laps
8. Marcs Ericsson - Sauber - 1:27.555 - 88 laps
9. Pascal Wehrlein - Manor - 1:28.292 - 54 laps
10. Romain Grosjean - Haas - 1:28.399 - 31 laps
11. Jolyon Palmer - Renault - 1:29.356 - 37 laps