The three-hour session was made optional as a result of the late arrival of the freight in Qatar, which forced the postponement of the test at the Losail International Circuit from Saturday and Sunday to Monday and Tuesday.
Norman Nato was quickest of the three Hypercar class entries that took part after getting down to a 1m41.822s aboard the #12 Porsche 963 LMDh.
That put him nearly a second and a half up on the sister #38 car in which Jenson Button posted a 1m43.206s.
The #38 Jota entry was quickest for the entire session, Will Stevens getting down to a 1m43.595s initially before Callum Ilott improved to 1m42.640s and then Nato to 1m42.459s.
The only other entry from the 19-car Hypercar field to participate was the Duqueine-run Isotta Fraschini Tipo 6 LMH Competizione.
The Italian Le Mans Hypercar developed by Michelotto Engineering ended up a distant third in the times after failing to complete a flying lap over the first two hours.
Jean-Karl Vernay eventually got down to a 1m45.928s in the Isotta, which is set to make its race debut in this weekend’s Qatar 1812Km WEC season-opener.
The six cars in the new LMGT3 class were headed by the best of the United Autosports McLaren 720S GT3 Evos.
Brazilian Nicolas Costa set a 1m56.583s in the final hour to just shade Charlie Eastwood’s fastest time for the TF Sport Chevrolet squad that had stood as the class best.
Eastwood was less than a tenth behind in the Chevrolet Corvette Z06 GT3 R on a 1m56.634s, although he lost a slightly faster time to a track limits violation.
Nico Pino jumped to third in class right at the end of the session in the second United McLaren with a 1m56.679s.
Fourth quickest was Michelle Gatting aboard the Iron Dames Lamborghini Hurcan GT3 EVO2 with a 1m57.081s.
Daniel Juncadella took fifth quickest in the second TF Chevrolet and Matteo Cressoni brought up the rear in the Iron Lynx Lamborghini.
All six of the LMGT3 entries to take part in session one of the Prologue had arrived at the Losail circuit before the arrival of the official freight delivery, which started on Saturday afternoon.
The United McLarens and TF’s Corvettes had tested in Dubai earlier this month, while the Iron Lynx Lambos were airfreighted to the Middle East.
The seafreight, which included the majority of the cars competing in LMGT3 and the Ganassi-run Cadillac V-Series.R LMDh, was delayed as a result of the geopolitical situation in the Red Sea.
That resulted in the freight being unloaded in Jeddah and trucked across Saudi Arabia to Qatar.
The second session of the Prologue, in which participation is mandatory, starts at 6pm local time and finishes at 11pm.
