Charles Leclerc ended his first test as a Ferrari Formula 1 driver quickest as he improved on Sebastian Vettel's Tuesday time to top the post-season Abu Dhabi test.
The purpose of the test was to give the 10 teams experience of Pirelli's 2019 compounds and make comparisons to the 2018 tyres.
Leclerc went faster than Vettel's benchmark after just a few hours and improved early in the afternoon on Pirelli's 'Compound 5' tyre - the 2019 hypersoft - to end up on a 1m36.450s.
Vettel's time from Tuesday was set on the 2018 hypersoft. The new-spec of that compound is thought to offer similar performance but has been improved to suffer less graining.
That was 1.7s slower than the pole time for Sunday's Abu Dhabi GP, a 1m34.794s set by Lewis Hamilton.
Pierre Gasly, driving for Red Bull ahead of his own 2019 move, remained Leclerc's closest challenger.
The Frenchman was 1.5s adrift after spending most of the day on a 1m37.976s, before improving twice in the final hour - first by four-hundredths of a second and then by another two-hundredths to end on a 1m37.916s. He too used Compound 5.
Lance Stroll ended his first full day driving a Racing Point Force India third-fastest as he awaits confirmation of a race drive with the team for 2019.
The Canadian's 1m38.044s, set at the start of the afternoon on 2018-spec hypersofts, remained his best effort for the day.
Mercedes' Compound 5-shod Valtteri Bottas finished fourth fastest, like Stroll with a lap time set in the first half of Wednesday's nine-hour session.
Carlos Sainz Jr jumped up the order with a 1m38.547s, set on 2019 hypersofts in the final hour, to end his McLaren debut fifth-fastest for the day.
He edged Renault's Artem Markelov by half a tenth, while 2019 Williams driver George Russell - like Markelov on 2018 hypersofts - emulated Sainz's rise by leaping to seventh on a 1m38.802s after taking over from Robert Kubica (2018 hypersofts) for the final few hours.
Toro Rosso returnee Daniil Kvyat and Haas's F1 test debutant Louis Deletraz both used Compound 5 to split the new Williams team-mates.
Antonio Giovinazzi completed the 11 runners. The Sauber driver caused a red flag when he stopped in the tunnel exiting the pitlane in the afternoon.
Day two times
|2||Pierre Gasly||Red Bull/Renault||1m37.916s||1.466s||129|
|3||Lance Stroll||Force India/Mercedes||1m38.044s||1.594s||122|
|8||Daniil Kvyat||Toro Rosso/Honda||1m38.862s||2.412s||155|