Sebastian Vettel topped the timesheets on Tuesday in Formula One's pre-season testing at the Circuit de Barcelona-Catalunya in Spain.
The Ferrari driver set a time of one minute, 20.396 seconds on soft tyres in the morning session, putting him narrowly ahead of Mercedes' Valtteri Bottas and Red Bull's Max Verstappen, while McLaren had a day to forget.
World champion Lewis Hamilton went out in the afternoon session and managed a lap of 1:20.808 to place fourth fastest.
Here is a look at the top times, per Formula 1:
The teams were clearly eager to make up for lost time after the weather disruptions last week, as they immediately set about getting laps under their belt.
Bottas was the first to set a time within minutes of the early session starting, as he recorded a 1:23.870, which he continued to improve on throughout the morning.
The Finn racked up a total of 86 laps before lunch, the same number as Vettel and one more than Verstappen, with the trio at one point incredibly close to one another, per F1's official Twitter account:
Vettel would ultimately set the pace, though, with his effort shortly before the final half hour of the early session proving the quickest.
The four-time world champion also ended the day having completed the most laps. Vettel finished on 168 laps, Verstappen on 127 and Marcus Ericsson on 118.
It was not a good morning for McLaren, as they saw Stoffel Vandoorne break down twice inside the opening hour, with the second instance bringing out the red flags after a power shutdown:
He was able to get out on track again in the final minutes of the session, bringing his lap total to a meagre seven.
Things got little better in the afternoon when a hydraulics fault ended McLaren's running for good on Tuesday with only 38 laps completed, per Sky Sports F1:
Sergio Perez of Force India also prompted the red flag to come out midway through the morning after he spun into the gravel at Turn 4.
Meanwhile, there was another red flag in the afternoon when Verstappen's Red Bull came to a halt at Turn 1.