Lando Norris finished the first day of pre-season testing in Barcelona as the fastest driver, the McLaren man setting the quickest time in the final hour of running.
With Charles Leclerc setting the pace early on Wednesday morning as he set a 1:20.165 to lead into the lunchtime break, Carlos Sainz stepped into the F1-75 to continue Ferrari's testing programme during the afternoon.
Sainz quickly slotted into second place behind Leclerc, setting a 1:20.416 on the Medium (C3) compound to make it a Ferrari 1-2 as the final hour of the day began.
However, Norris fitted a set of Softs (C4) with 30 minutes remaining and headed out to put in a 1:19.951, as the British driver took over at the front ahead of Leclerc and Sainz. With 15 minutes remaining, Norris went faster again as he fitted another fresh set of Softs to put in a 1:19.568 after going quickest in all three sectors.
However, the afternoon wasn't all plain sailing for McLaren, as Norris also suffered an apparent minor technical issue in the pit lane as he ground to a halt and required retrieval by his mechanics. Norris finished the day with a total of 103 laps of the circuit.
After appearing in the morning session, George Russell finished in fourth place on his maiden day as a full-time Mercedes F1 driver – ahead of teammate Lewis Hamilton.
The seven-time World Champion got behind the wheel of the W13 for the afternoon and finished the day two-tenths of a second behind Russell.
Verstappen leads the way on the mileage charts
Aston Martin's Sebastian Vettel was sixth, despite only taking part in the morning session, with Yuki Tsunoda an encouraging seventh for AlphaTauri. The Japanese driver, entering his sophomore season with the team, was one of the highest-mileage drivers on the day as he completed 121 tours of the Catalunya circuit.
But the clear winner, in terms of individual lap count, was Max Verstappen. The reigning World Champion clocked up 147 laps over the course of the day to complete more than two complete Grand Prix distances on his way to ninth on the timesheets.
On what was a surprisingly calm day of track action, Verstappen had the only notable off-track excursion as he went off into the gravel – the Dutchman able to return to the pits without any consequences to his day.
Verstappen's 147 laps for Red Bull were also only eclipsed by one team. Ferrari collectively beat his mileage count by just six laps, as Sainz stayed out on track in the final minutes of the afternoon. Mercedes also weren't far off, as they racked up 127 laps over the course of the day between their two drivers, while Williams accumulated 132 laps.
Fernando Alonso was a late improver for Alpine as he rose to eighth in the final minutes, while Valtteri Bottas placed ninth on his official first day as an Alfa Romeo F1 driver.
For all the revolutionary technology on display as F1's new technical era began in earnest, the day was noteworthy for how few reliability issues there were.
There were problems for Haas during the afternoon, with Mick Schumacher missing out on most of the session as a result of a damaged floor that meant the VF-22 required extensive work back in the garage. He was able to rejoin the action with 35 minutes remaining in the day.
Alfa Romeo also were playing catch-up for most of the afternoon, after Robert Kubica's morning was compromised by a floor issue on the C42.
Haas and Alfa Romeo were the two lowest-mileage teams of the day, with 43 and 32 laps put in respectively.
Testing resumes at 09:00 local time on Thursday morning.
With F1 pre-season testing getting underway in Barcelona this week, our journalists Dieter Rencken, Mike Seymour and Thomas Maher look ahead to what to expect.