Alfa Romeo’s Zhou Guanyu ended the second day of pre-season testing from the Bahrain International Circuit as the fastest driver.
Zhou’s fastest lap came in the final half hour of the session as he took to the track with a set of C5 tyres.
The Chinese driver, who enters his second year in F1, headed reigning World Champion Max Verstappen on the time sheet.
However, the day ended on a sour note for Zhou, as he had to be wheeled back to the garage from the end of the pit lane after an issue occurred while he was practicing a start.
Verstappen took over from team-mate Sergio Perez in the evening session with his best time sitting just 0.040s down on Zhou.
Fernando Alonso was third for Aston Martin as he took control of the AMR23 car for the entire day.
However, he will have just a half day of running on Saturday as the team has confirmed that Felipe Drugovich will be back behind the wheel once again as speculation grows that he will race in place of an injured Lance Stroll next week.
Running in the first half of the day was uninterrupted, but a red flag was called in the evening after George Russell came to a halt on the track.
Mercedes confirmed that it was a hydraulic issue that hit the W14 car, which kept the car in the garage for the remainder of the day.
Nyck de Vries was fourth for AlphaTauri as he prepares for his rookie F1 season while returnee Nico Hulkenberg rounded out the top five.
Both Ferraris ended up inside the top 10, with Carlos Sainz and Charles Leclerc sitting in sixth and eighth.
Logan Sargeant was seventh and tallied the most laps of any driver, clocking 154 laps during the day.
Oscar Piastri was ninth, while Pierre Gasly was 10th fastest for Alpine.
Pre-season testing from Bahrain will continue on Saturday, which will mark the final day of running ahead of the new campaign.