Esteban Ocon put Alpine at the top of the timesheets during Friday morning's early testing action in Bahrain, which was halted when Nicholas Latifi's Williams caught fire.
Latifi's rear brakes lit up in the braking zone for Turn 12 shortly before the two-hour mark, sending him into a spin and bringing out the red flags.
As flames dramatically engulfed the rear of the car, the rear-left tyre exploded, after which marshals were able to get the situation under control, with an unharmed Latifi assisting.
Up to that point, Ocon had posted the fastest time of the session, working his way down to a 1:34.276 on the Soft (C4) tyre, while also sporting an all-pink livery on the Alpine.
Ferrari's Charles Leclerc, who used the C3 Medium, was just under a tenth adrift in P2.
Aston Martin lead the mileage charts, more issues for McLaren
Aston Martin's Sebastian Vettel was the most productive driver before the red flag, racking up 35 laps, while Red Bull's Max Verstappen (26) and Ocon (24) also enjoyed smooth starts to their programmes.
Verstappen was third fastest, a second-and-a-half away from Leclerc, having used the Hard C2 rubber, while Alfa Romeo's Valtteri Bottas (C2) and AlphaTauri's Yuki Tsunoda (C3) completed the top five positions.
There was further trouble for McLaren, after their brake issues on the opening day, with the problem appearing to persist into Friday's running.
Lando Norris again stood in for the unwell Daniel Ricciardo - with McLaren clarifying that the Australian has not tested positive for COVID-19 - and was only able to complete six laps over the first two hours.
With Latifi's car being cleared away, the session is due to resume at 12:16 local time (09:16 GMT).
You can stay up to date with all the action from Bahrain in the dedicated RacingNews365.com live blog.
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