Sebastian Vettel and Ferrari topped the opening day of pre-season testing in Barcelona on Monday.
The German remained not only the day's fastest driver in the afternoon session but also the most diligent at work as he put 156 trouble-free laps under his belt.
Vettel ended the day 0.5s clear of McLaren's Carlos Sainz and almost a second faster than Haas' Romain Grosjean in third.
Pre-season test Day 1 - afternoon
| Pos | Driver | Team | Time | Laps |
|---|---|---|---|---|
| 1 | Vettel | Ferrari | 1:18.161 | 168 |
| 2 | Sainz | McLaren | 1:18.558 | 117 |
| 3 | Grosjean | Haas | 1:19.159 | 63 |
| 4 | Verstappen | Red Bull | 1:19.426 | 127 |
| 5 | Raikkonen | Alfa Romeo | 1:19.462 | 113 |
| 6 | Kvyat | Toro Rosso | 1:19.464 | 76 |
| 7 | Perez | Racing Point | 1:19.944 | 30 |
| 8 | Bottas | Mercedes | 1:20.127 | 69 |
| 9 | Hamilton | Mercedes | 1:20.135 | 78 |
| 10 | Hulkenberg | Renault | 1:20.980 | 65 |
| 11 | Ricciardo | Renault | 1:20.983 | 44 |
As scheduled, Lewis Hamilton was slotted into the seat of Mercedes' W10 in place of Valtteri Bottas for the afternoon session, but the reigning world champion took his time to get up to speed.
Over at Renault, Daniel Ricciardo took over from Nico Hulkenberg, but the Aussie remained confined to the garage for the first hour of running.
Meanwhile, Vettel picked up where he had left off earlier, resuming his workload with an 18-lap stint onboard the Scuderia's SF90 that has been running flawlessly since this morning.
Sixty minutes into proceedings, McLaren's Carlos Sainz, after racking up 56 laps in the morning, ground to a halt at the end of the pitlane just 60 minutes into the afternoon session, the Spaniard's car appearing to lose drive.
The first significant improvement in the afternoon came from Kimi Raikkonen who put his Ferrari-powered Alfa Romeo P2 on the time-sheet, under 1.5s adrift from Vettel.
The second jump up the order was courtesy of Daniil Kvyat, who charged from the bottom of the time-sheet to fourth with a lap in the 1.19s.
Vettel remained busy but had reined in the speed, the four-time world champion focusing on long runs with his C3-shod SF90.
Spending the bulk of his afternoon third fastest, with a lap in 1m19.600, Max Verstappen was the second driver after Vettel to reach the 100-lap mark.
Running down the order but still getting acquainted with his mount - and team, Ricciardo equaled the best effort by team mate Nico Hulkenberg.
As the afternoon session entered its last hour, Romain Grosjean's name popped up on the timing screen, the Frenchman placing his Haas second, but his 1m19.320 was still almost 1.2s off Vettel.
Thirty minutes later, McLaren fans rejoiced when Carlos Sainz took the runner-up spot with a 1m19.318 that just edged Grosjean. But the Haas man was determined to hold on to his spot, and he promptly lowered his time to beat Sainz by 0.156s.
The Spaniard would have none of it however, the McLaren - fitted with a set of C4 super soft rubber - putting a 1m18.558 on the board.
While Ferrari topped the first time sheet of the year, front-running rivals Red Bull and Mercedes showed no interest in showcasing their outright performance, with both outfits working on learning about and fine-tuning the baseline of their respective packages.
Verstappen ended the day P4 while Hamilton logged in the data to conclude his first day of testing for 2019 down in P9.
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