Antonio Giovinazzi topped the opening session of the second Formula 1 pre-season test in Barcelona on Tuesday as Ferrari lost track time due to checks on its cooling system.

After seeing Red Bull's Pierre Gasly set an early benchmark in the Honda-powered RB15, Giovinazzi managed to edge ahead and grab P1 with 20 minutes remaining in the morning session, posting a best lap time of 1m18.589s.

Gasly was left to settle for second place, 0.058 seconds down on Giovinazzi, but still finished just ahead of Ferrari's Charles Leclerc, who lost most of the morning due to a number of checks on the cooling system on his SF90 car.

Leclerc managed six early laps before spending a couple of hours stuck in the pits as the team completed a number of checks on the car. The Monegasque driver ultimately got out to complete 30 laps for the morning, finishing within one-tenth of Giovinazzi at the front.

Leclerc will hand over to Ferrari teammate Sebastian Vettel as planned this afternoon despite the lost track time.

Lance Stroll took P4 for Racing Point ahead of Kevin Magnussen, who managed more than one race distance for Haas en route to fifth place.

George Russell gave Williams its most productive session yet with the new FW42 car, completing 46 laps and finishing sixth-fastest as the team pushed to make up for the time it lost last week. Alexander Albon finished seventh for Toro Rosso with 39 laps on the board.

Lewis Hamilton debuted a number of updated parts on the Mercedes W10 as the team looked to recover from a difficult start to testing last week, and managed 83 laps in P8. Hamilton will hand the reins of the car to teammate Valtteri Bottas this afternoon.

Nico Hulkenberg took P9 for Renault, also managing over one race distance, while Lando Norris finished down in 10th for McLaren after causing the only red flag of the day when his car stopped at Turn 3 during the third hour. Norris did not return to the track after the issue.

Running resumes at 2pm local time in Barcelona (1pm UK), continuing for another four hours.