A smart tire call from Audi Sport Team Attempto put the German outfit’s No. 66 car into the race lead before momentum swung back to Audi Sport Team Sainteloc during a safety car period as the Total 24 Hours of Spa entered its final stages.
After Audi established a one-two for its remaining factory-supported just before the 18-hour mark, Attempto got the upper hand on Sainteloc by giving Frederic Vervisch a set of wets against Markus Winlelhock who remained on slicks.
The move was a gamble because the anticipated heavy rain had only started out as a light drizzle which initially favored the slick-shod front-runners.
With just over four hours to go, Vervisch emerged from the pits ahead of Winkelhock before the double 24H Spa winner got past with an overtake at the left-hander after Bruxelles.
That wasn’t to be the end of the battle as the momentum swung back and forth, with Vervisch powering Attempto back into the lead out of La Source.
Winkelhock then regained the advantage briefly but Vervisch refused to back off, and with the track clearly favoring the wet Pirelli compound made another defining pass at Campus, after which the lead grew.
With the rain intensifying, Sainteloc brought Winkelhock into the pits for wet tires with just over three and a half hours to go, along with the two front-running Ferrari 488 GT3 Evo 2020s and the Haupt Racing Team Mercedes-AMG GT3 Evo.
These earlier-than-planned stops gave Vervisch a huge advantage of one minute 39 seconds, although the gap came down slightly before the Belgian pitted on schedule shortly before the race hit three hours to go.
Right on the 22-hour mark, a Full Course Yellow and safety car was called for the No. 33 Team WRT Audi going off into the left-side barriers at Raidillon, prompting the cars that had stayed out for longer on slicks to come in for more wets.
The fact that Vervisch pitted under green while his rivals came in under the controlled pace conditions meant the Attempto driver’s advantage transferred over to Dorian Boccolacci who took over from Winkelhock.
James Calado was third in the AF Corse Ferrari, ahead of SMP Racing Ferrari driver Sergey Sirotkin and the ROWE Racing Porsche 911 GT3 R of Nick Tandy.