Kawasaki rider Tom Sykes set the pace on both days of the first collective pre-season World Superbike test of the 2016 season.
Sykes ended up two tenths clear of nearest rival Chaz Davies (Ducati) on the opening day of the test on Tuesday, setting a benchmark of 1m40.882s.
The Yorkshireman then made a late move to the top of the timesheets on Wednesday, becoming the only rider to dip beneath the 1m40s mark with a best time of 1m39.924s.
That put Sykes marginally clear of works Ducati duo Davide Giugliano and Davies, the former falling just 0.123s short of the spot with a 1m40.047s.
Davies rounded out the top three, less than a tenth behind his teammate, while Honda Ten Kate riders Nicky Hayden and Michael van der Mark rounded out the top five.
Ducati privateer Xavi Fores enjoyed a spell at the top of the timesheets before eventually slumping to sixth, with Jonathan Rea (Kawasaki) the only other man to lap within a second of Sykes.
The reigning champion was third quickest on the opening day, but ended up only seventh on Wednesday ahead of the factory Yamahas of Sylvain Guintoli and Alex Lowes.
British Superbike champion Josh Brookes, having his first run on the Milwaukee BMW, rounded out the top 10, lapping some eight tenths quicker than ex-MotoGP teammate Karel Abraham.
Full Jerez testing times:
|Pos.||Rider||Bike||Day 1||Day 2|
|5||Michael van der Mark||Honda||1m41.891s||1m40.601s|
|11||Leon Camier||MV Agusta||1m42.896s||1m42.182s|
|12||Karel Abraham||BMW||no time||1m42.628s