Sebastian Vettel and Ferrari began Formula 1 2019 pre-season testing on top as the four-time World Champion set the fastest time on the opening morning.
Vettel, having moved to the front early on, improved on his initial benchmark by moving into the 1:18s, ultimately winding up with a lap of 1:18.161, as the new 2019 machines broke cover at a sunny Circuit de Barcelona-Catalunya.
Vettel’s time came during the final half hour at the Spanish Grand Prix venue, with the lap already quicker than the best achieved at last year’s opening four-day encounter.
Gallery: Check out the best images from the opening day of testing
Vettel was also the most productive driver during the morning session, completing over a race distance’s worth of laps aboard the SF90.
Vettel’s lap left him 1.7s clear of Sergio Perez, who debuted the Racing Point RP19 during the opening moments of the day, following last week’s livery launch.
Valtteri Bottas put Mercedes’ W10 through its paces and classified third, with reigning World Champion Lewis Hamilton due to take over for the afternoon session.
Kimi Raikkonen’s Alfa Romeo career began in inauspicious circumstances as he caused a red-flag period just five minutes into the action, spinning into the Turn 5 gravel on his out-lap.
Raikkonen’s Alfa Romeo C38 was soon recovered to the pit lane and he was able to resume his programme shortly afterwards.
Max Verstappen racked up over 50 laps in the Red Bull-Honda as the on-track partnership between the respective parties began in earnest, while Carlos Sainz Jr. was sixth for McLaren.
Renault’s Nico Hulkenberg was seventh, while Haas’ Romain Grosjean completed the fewest laps after his VF-19 came to a halt on track, causing a brief stoppage to proceedings.
Daniil Kvyat brought up the nine participants ahead of his return to Formula 1 after a year’s absence, finishing 3.6s behind Vettel.
Williams is not participating in today’s action after confirming on Sunday that its FW42 was not yet ready. The team intends to join its rivals for Tuesday’s second day of running.
Testing will resume at 14:00 for a further four hours of running.
| Pos | Driver | Team | Time | Gap | Laps |
| 1 |  Sebastian Vettel | Ferrari | 1:18.161 | 72 | |
| 2 |  Sergio Perez | Racing Point | 1:19.944 | 1.783 | 20 |
| 3 |  Valtteri Bottas | Mercedes | 1:20.127 | 1.966 | 69 |
| 4 | Kimi Raikkonen | Alfa Romeo | 1:20.160 | 1.999 | 46 |
| 5 |  Max Verstappen | Red Bull | 1:20.174 | 2.013 | 52 |
| 6 |  Carlos Sainz | McLaren | 1:20.430 | 2.269 | 56 |
| 7 | Nico Hulkenberg | Renault | 1:20.980 | 2.819 | 65 |
| 8 |  Romain Grosjean | Haas | 1:21.500 | 3.339 | 18 |
| 9 |  Daniil Kvyat | Toro Rosso | 1:21.732 | 3.571 | 35 |
