Jolyon Palmer put Lotus on top of the times on the second and final day of Formula 1 testing at the Barcelona circuit on Wednesday.
The Briton, taking over from Pastor Maldonado at the wheel of the E23, jumped to first place with some 15 minutes of the session left thanks to a run on super-soft tyres.
Palmer's best of 1:26.080, nearly two seconds slower than yesterday's benchmark, put him ahead of Pascal Wehrlein, who had looked set to finish quickest before the Lotus driver's late run.
The German driver, who missed yesterday's session after feeling unwell, took over from Spanish Grand Prix winner Nico Rosberg at the wheel of the W06.
Despite admitting that he was still not feeling 100 per cent, Wehrlein had no trouble covering over 130 laps. He set his best time with medium tyres.
Pierre Gasly finished in third for Red Bull, the Frenchman switching from Toro Rosso, also using medium tyres.
McLaren, who sat at the bottom of the times on the opening day, finished in fourth position today thanks to a run of super-soft tyres by Jenson Button, who spent the day carrying several aerodynamic tests for the team.
The Briton had a productive session, covering 100 laps.
Williams test driver Alex Lynn made his debut with the team and posted the fifth fastest time. He managed just 52 laps, the fewest today.
Another man testing new machinery was Formula 3 European champion Esteban Ocon, who drove for Force India.
The Frenchman was sixth quickest ahead of Mexican Esteban Gutierrez, who also made his debut at the wheel of this year's Ferrari, and the Toro Rosso of Carlos Sainz.
Rafaelle Marciello finished at the bottom of the times for Sauber after crashing early in the morning.
The Italian damaged the Sauber after going off at Turn 3, and he was unable to take the track again until after the lunch break. He still managed 75 laps.
Marciello caused one of three red flags seen today, the other two triggered by Gasly and Sainz stopping at the pit exit and the pit entry respectively.
|3.||Pierre Gasly||Red Bull-Renault||1:26.683||+0.603||75|
|6.||Esteban Ocon||Force India-Mercedes||1:27.520||+1.440||94|
|8.||Carlos Sainz||Toro Rosso-Renault||1:27.997||+1.917||125|