Ferrari laid down a marker to the likes of Red Bull and Mercedes as Charles Leclerc delivered the fastest laps of pre-season so far at Barcelona. Running was halted for a big crash for a second day running at the Circuit de Catalunya, as Pierre Gasly suffered a big crash in the Red Bull.
The two newcomers in Formula 1's big three were in the headlines, albeit for very different reasons on Thursday.
After Alexander Albon had delivered a mightily impressive lap of 1:16.882 for a Toro Rosso team making a habit of hitting the upper reaches of timesheets this testing period, Leclerc put the Thai drivers' time into context as he lowered it three times on one-lap bursts.
The Monegasque hit lunch having lowered the benchmark to 1:16.231 – a time good enough for third on the grid in last year's Spanish Grand Prix and almost a second faster than the quickest lap seen here at this time last year – delivered by new team-mate Sebastian Vettel on that occasion.
Gasly had earlier hinted at Red Bull beginning to test the limits, clocking 1:17.084, by a decent margin the team's best time so far.
However, the Frenchman's continued pushing of the boundaries took him off the track at turn nine and into the barriers at seemingly considerable speed.
The RB15 suffered all-around damage and will likely require work long into the night in order for Max Verstappen to make it out to complete the team's programme on Friday.
In a promising development for Williams, George Russell completed more laps than any driver, with 140 to his name. Indeed only Mercedes (181 between Lewis Hamilton and Valtteri Bottas) toured the Circuit de Catalunya more times than Williams, whose recovery from the delay in getting the FW42 continues.
Lap counts as of the end of yesterday - Williams have made good ground this week, but Racing Point are behind on mileage due to the team being short on parts and are currently prioritising a major upgrade of their car to be ready for the first race in Melbourne. #F1Testingpic.twitter.com/rlgLIF75vX
— Rob Watts (@robwattsf1) February 28, 2019