Sebastien Buemi overtook his Toyota teammate Mike Conway to lead the opening stint of the Total 6 Hours of Spa in the No. 8 Toyota GR010 Hybrid.
Buemi started from second on the grid and briefly slipped behind United Autosports LMP2 driver Phil Hanson after the first corner, but quickly regained the place and set about pursuing his teammate Conway in the No. 7 Toyota.
Buemi passed Conway into La Source after around 20 minutes and led the remainder of the opening stint.
The race leader then had a messy first pit stop in which his No. 8 car’s refueling hose was removed around six seconds earlier than the minimum time.
The error meant Buemi retained his lead over Conway, while Andre Negrao ran third at the end of the first hour in the Alpine Endurance Team A480 Gibson LMP1 car.
Negrao, who started fourth alongside Hanson, fell behind two more LMP2 cars in the opening exchanges but worked past the trio ahead to be five seconds behind the Toyotas at the end of the first hour.
Negrao pitted at the end of lap 21, while the Toyotas pitted after 24 and 25 laps respectively with Conway coming in first.
Hanson led the LMP2 class by a second from Racing Team Nederland’s Giedo van der Garde after one hour of racing, with DragonSpeed’s Juan Pablo Montoya in third.
However, Montoya was called to serve a stop-go penalty for his role in sending the GTE-Am pole-sitting TF Sport Aston Martin Vantage GTE into a wild spin at Pouhon.
Montoya was adjudged to have moved right into the side of his LMP2 rival Roman Rusinov, who in turn tapped Ben Keating’s Aston Martin.
In GTE-Pro, Porsche’s Kevin Estre dominated from pole and built up a lead of almost 10 seconds from the two AF Corse Ferrari 488 GTE Evos during the first hour.
The Frenchman retained his advantage through the first round of pit stops, leading from Alessandro Pier Guidi, Miguel Molina and Richard Lietz.
Porsche factory driver Matt Campbell worked his way past the Bronze-rated drivers in GTE-Am to lead the category in the No. 77 Dempsey-Proton Racing 911 RSR-19 which started from the back of the grid after an accident during qualifying.
Campbell passed Keating into La Source to capture the lead, while Tomonobu Fujii followed the Australian through in the D’station Racing Aston Martin shortly after.
Two cars did not take the start of Saturday’s race. A suspected fuel leak prevented ARC Bratislava’s Ligier JS P217 Gibson from arriving onto the grid, while GR Racing’s GTE-Am Porsche was withdrawn after a crash for Mike Wainwright during the warm-up.