Kamui Kobayashi and Sebastien Buemi ended up 1-2 in their respective Toyota GR010 HYBRID Le Mans Hypercars, setting their times straight after a 45-minute stoppage in Free Practice 1 for the Bahrain 8 Hours.
The red flag resulted from a loose advertising hoarding being blown onto the track by high winds and then attention to banners elsewhere around the Bahrain International Circuit.
Buemi had been fastest before the break with a 1m49.976s, which he improved to a 1m49.960s straight after the resumption.
Kobayashi then went almost exactly a tenth faster with a 1m49.856s to end up quickest.
The four Porsche 963 LMDhs in the WEC Hypercar field filled out positions three to six, the two Penske-run factory cars sandwiched between the two customer entries.
Gianmaria Bruni was fastest of the Porsche pack in third place with a 1m50.290s set immediately after the stoppage aboard Proton Competition’s car.
Laurens Vanthoor was just three hundredths behind in the first of the Penske cars with a 1m50.328s, while Michael Christensen was less than a tenth behind on 1m50.403s in the US team’s other entry.
Will Stevens took sixth aboard the Jota Porsche on 1m50.507s.
The solo factory Cadillac V-Series.R run by Chip Ganassi Racing was seventh courtesy of a 1m50.542s from Alex Lynn
Ferrari took eighth and ninth in the FP1 classification, James Calado’s 1m51.482s aboard the best of the 499P LMHs shading Miguel Molina’s 1m51.722s in the sister car.
The two Peugeot 9X8 LMHs ended up 10th and 11th in the hands of Nico Muller and Paul di Resta ahead of the Vanwall Vandervell 680 LMH with Esteban Guerrieri driving.
FP1 had been declared wet on its resumption as a result of spots of rain reported at handful of corners.
The session was quickly extended to its full 90-minute duration to take account of the stoppage, but the rain intensified with just over half an hour.
This brought the entire 36-car field into the pits, with only a handful of cars returning to a wet but drying track for the final minutes.
Filipe Albuquerque was quickest in LMP2 for the United Autosports squad after trading fastest times with Gabriel Aubry in Vector Sport ORECA-Gibson 07.
Albuquerque got down to a 1m54.100s, which gave him a margin of more than half a second over Aubry’s beset of 1m54.654s.
Ferdinand Habsburg took third for WRT ahead of Oliver Rasmussen in Jota’s LMP2 entry.
The TF Sport-run D’Station Aston Martin Vantage GTE ended up quickest in GTE Am with Tomonobu Fujii’s hands.
The Japanese driver’s 1m59.516s was just six thousandths ahead quicker than Daniel Serra’s best in the Kessel Ferrari 488 GTE.
Second practice for the Bahrain race is due to start at 17:30 on Thursday.