Ferrari junior Antonio Giovinazzi topped the first day of testing at the Hungaroring, smashing Sebastian Vettel's official lap record after a 1m15.648s run on Pirelli's hypersoft tyre.
The young Italian picked up after lunch where he left off in the morning, accumulating a total of 96 laps over a productive day as he handled the Scuderia's various development programmes for its SF71-H.
Giovinazzi's best time was almost 2.5s faster than Sauber's Marcus Ericsson who ended the day second on the timesheet.
The afternoon session was interrupted by a red flag, courtesy of Toro Rosso's Sean Gelael, who was conducting development work for Pirelli when he crashed at high speed at the Hungaroring's Turn 11.
Brendon Hartley, also using the hypersoft compound, clocked in with the third fastest time, while Lando Norris put McLaren fourth.
A downpour 90 minutes from the end of the session reduced track activity and any opportunities to improve times. However, Norris and Red Bull's Daniel Ricciardo braved the wet conditions to run some laps on the intermediates.
The Aussie was among those, along with Force India's Nicholas Latifi and Williams Oliver Rowland, to trial a new 2019-specification front wing.
1. Antonio Giovinazzi, Ferrari, 1m15.648s 96 laps
2. Marcus Ericsson, Sauber, 1m18.155s 95 laps
3. Brendon Hartley, Toro Rosso, 1m19.251s 126 laps
4. Lando Norris, McLaren, 1m19.294s 107 laps
5. George Russell, Mercedes, 1m19.781s 49 laps
6. Daniel Ricciardo, Red Bull Racing, 1m18.854s 125 laps
7. Nicholas Latifi, Force India, 1m19.994s 103 laps
8. Nico Hulkenberg, Renault, 1m20.826s 63 laps
9. Oliver Rowland, Williams, 1m21.594s 65 laps
10. Sean Gelael, Toro Rosso, 1m21.451s 109 laps (Pirelli)