Barrier repairs that started before the 12-hour point continued through the night, with cars under full course yellow while circuit staff worked on both sides of the Kemmel Straight at the 24 Hours of Spa.
Initially predicted to take an hour, then an additional 20 minutes, until the 13-hour point was passed still under caution, despite continued dry conditions.
The total full-course yellow and Safety Car period lasted from 3:33 am local time until the restart at 5:41 am, with 55 of the starting 70 cars still running. At the green flag, Calan Williams in the #30 WRT BMW led the gold class, running in overall 13th.
The #75 Sun Energy 1 Mercedes, with Chaz Mostert at the wheel, received a 15-second time penalty to be served at its next pit stop, shortly after the restart.
The car had been noted for speeding in the pit lane, adding another challenge to a recovery drive from a pit lane start and driver change following Kenny Habul’s Thursday night crash.
Just past the 13-hour mark, it was back to full-course yellow following the #19 Iron Lynx Lamborghini going off and into the gravel at Stavelot. A relatively short full-course yellow was repeated an hour later when the #89 Akkodis Mercedes spun off into the grass at Eau Rouge, quickly retrieved.
Unlike the six and 12-hour marks, points are not awarded to cars leading their classes after 18 hours. However, it was the #98 Rowe BMW in the outright lead as the hour ticked over.
In the Gold Cup, the #5 Optimum McLaren led over the #30 WRT BMW, albeit with the latter a pit stop ahead after a lengthy overnight drive from Calan Williams.
The large Bronze field was led by the #91 Herberth Porsche, with the #79 Haupt Mercedes of Jordan Love running eighth in class.
The #23 Grove Porsche was 12th in class, Earl Bamber handing over for team-mates to complete mandatory stints, whilst the #3 GetSpeed Mercedes’ struggles continued, running 14th in the class and four laps down from the Herberth car.
The Sun Energy 1 Mercedes, with Nicky Catsburg driving at the 18-hour point, had regained the lead of its class and was a lap ahead of the #24 Car Collection Porsche. In Silver, the #99 Tresor Orange 1 Audi continued to lead.
Lamborghini, which had looked like one of the strongest manufacturers through qualifying, lost seven of its 10 starting cars overnight.
Retirements put Brendon Leitch, in the #70 Leipart Lamborghini, and Ricky Capo, in the #58 Grasser Lamborghini, out of the running before the race’s halfway point.