Toyota development driver Kenta Yamashita was the fastest of the Japanese manufacturer's three rookies in the post-Bahrain World Endurance Championship test.
The 2019 Super GT champion posted a 1m44.075s time in the second of the two sessions of the so-called rookie test to end up just under half a second quicker than Toyota test and reserve driver Thomas Laurent.
Yamashita, who has been placed with the High Class LMP2 squad for the 2019/20 WEC, completed 34 laps in the #7 on Toyota TS050 HYBRID in the afternoon session of his first test run in an LMP1 car.
Laurent, who first got to test a TS050 at this year's official pre-season 'prologue' test at Barcelona in July, posted a 1m44.514s time after completing the same number of laps as Yamashita.
Mercedes Formula E driver Nyck de Vries, who was the official P1 rookie nominated by the WEC organisation after his performances in P2 with Racing Team Nederlands, was just five hundredths slower than Laurent.
The Dutchman lapped in 1m44.561s in the #8 Toyota on his first experience of a P1 car.
Toyota Motorsport GmbH technical director Pascal Vasselon told Autosport: "All three of our rookies were very good today: they didn't put a wheel off the track and were all quick."
Vasselon stressed that it was unfair to make comparisons between the three drives, pointing out that Yamashita was given two new sets of Michelin tyres compared with one for Laurent and de Vries.
The best time of the test was a 1m43.264s set by Kamui Kobayashi with a 1m43.264s effort set in the afternoon session.
Formula 2 and Haas Formula 1 simulator driver Louis Deletraz posted a 1m45.217 time in the Rebellion-Gibson R-13 on his first experience in a prototype.
The time he set over the course of 43 laps compared with the 1m44.867s effort with which Rebellion regular Norman Nato topped the times in the rain-affected morning session.
European Le Mans Series LMP3 champion Mikkel Jensen was the fastest rookie in the LMP2 class.
The 24-year-old Dane posted a 1m47.224s time in the G-Drive Racing team's ORECA-Gibson 07 in the afternoon session.
Jensen was officially nominated as the WEC's P2 rookie to drive the Signatech Alpine ORECA, in which he set a best time of 1m48.515s.
His fastest time compared with WEC regular Will Stevens' 1m46.855s class-best in the Jota-run Jackie Chan DC Racing ORECA.
The second-fastest rookie in the class was Super Formula driver Harrison Newey.
Newey posted a 1m47.829s in the TDS-run Racing Team Nederland Oreca, followed by Japanese Formula 3 racer Charles Milesi, who was half a second slower in the same car.
Long-time Corvette Racing driver Jan Magnussen was 10th overall with his best time of 1m50.568s in the High Class Oreca, with the effort set in the morning.
Ex-Formula 1 driver Roberto Merhi propped up the order for G-Drive with a 1m52.361s, which was also set in the first session.
The fastest newcomer in GTE was Aston Martin junior Andrew Watson in the #95 Vantage GTE.
The Gulf Racing regular posted a 1m57.139s in the afternoon session to get within 0.409s of Porsche driver Gianmaria Bruni's class-topping effort.
Nicklas Nielsen, who races for AF Corse in GTE Am, was the fastest Ferrari driver with his best time of 1m57.772s in the best of the 488 GTEs.
WEC and ELMS LMP2 regular Job van Uitert was ninth-fastest aboard the #92 Porsche 911 RSR.
Van Uitert set a 1m58.731s in the morning session over the course of 28 laps before returning to the car for a short run in the afternoon.
The designated rookie for GTE Am, Vincent Abril, was the second-best of the newcomers for the class behind American Maxwell Root, with both driving a Team Project 1 Porsche.