Toyota driver Sebastien Buemi led the opening hour of the Total 6 Hours of Spa after passing pole-sitter Norman Nato when the race got underway following a safety car start.
Buemi accelerated the No. 8 Toyota TS050 Hybrid away from Nato’s No. 1 Rebellion R13 Gibson coming out of La Source when the field was released after 14 minutes behind the safety car.
Mike Conway also got ahead of the Rebellion in the No. 7 Toyota to establish a one-two for the Japanese manufacturer, while Buemi set off at the front of the field.
The Swiss driver was around 12 seconds ahead when he overshot two corners and suddenly slowed with what Toyota described as an energy mapping issue. When Buemi got going again, the lead gap had tightened to around four seconds.
The No. 8 Toyota maintained its advantage through the opening round of pit stops by not taking new tires, while the No. 7 car opted for slicks which took longer.
Rebellion pitted early for a new set of wet tires which brought the R13 on a similar one-lap pace to the leading Toyota after initially struggling to keep up, while ByKolles Racing had an early technical issue.
Tom Dillmann overtook Nato for third at La Source but dropped behind the leading LMP2 when the ENSO CLM P1/01 Gibson’s seemingly temporary problem struck.
After a fully wet start, the conditions improved over the course of the opening stint to the point that slick tires became an option heading into the second hour.
Filipe Albuquerque dominated the opening stint in LMP2 for United Autosports and was the only person not to be affected by Giedo van der Garde’s charge from the back of the 29-car overall grid to second in the category.
In GTE-Pro, the lead changed three times during the opening stint as the cars from Porsche, Aston Martin and Ferrari put on an entertaining show.
Kevin Estre started from pole in the No. 92 Porsche 911 RSR-19 but was overtaken by Maxime Martin in the No. 97 Aston Martin Vantage GTE on the opening green flag lap.
Martin led for a handful of minutes before running wide at Bruxelles, which allowed Estre back through. At the same time, Martin’s teammate Marco Sorensen also slid out wide, which let Ferrari’s Alessandro Pier Guidi into third.
The AF Corse Ferrari driver then charged into the lead with a cornering move on Martin at the esses and a surge past Estre on the run down to Eau Rouge.
Richard Lietz also made up several positions and the No. 91 Porsche driver was second by the end of the stint, after getting past his teammate Estre in a duel lasting several laps.
Christian Ried led the opening hour of the GTE-Am class race in the No. 88 Dempsey-Proton Racing Porsche, from Team Project 1’s Egidio Perfetti and Ben Keating.