The 2021 TotalEnergies 24 Hours of Spa is on a knife-edge with three hours left to run.
The #51 Iron Lynx Ferrari still leads with Nicklas Nielsen at the wheel, but the battle with the #32 Audi Sport Team WRT car driven by Kelvin van der Linde has burst into life.
With three and a half hours to go Nielsen almost lost top spot whilst navigating heavy traffic, which gave Van der Linde an opportunity at the Bus Stop. The Audi driver briefly had his nose ahead, albeit with an armful of opposite lock and the circuit rapidly vanishing before his eyes. Nielsen held the advantage, while Van der Linde made contact in his effort to lap the #93 Ferrari soon afterwards.
The #51 Ferrari stopped seven minutes before the hour while the #32 Audi went a lap longer. For the second time in succession, the Iron Lynx crew were able to gain time, stretching Nielsen's lead from around one second to five. The #95 Garage 59 Aston Martin runs third at the 21-hour mark.
The #90 Madpanda Motorsport Mercedes-AMG still leads in the Silver Cup, as it has almost without exception since the second hour, but the battle for class honours is still impossible to call. The #159 Garage 59 Aston Martin is 20 seconds back while the #99 Attempto Racing Audi is also on the class-lead lap.
The Pro-Am contest is more settled with the #53 AF Corse Ferrari holding a one-lap advantage over the sister #52 car. Last year's winner, the #77 Barwell Motorsport Lamborghini, runs third with 180 minutes to run.
The sole remaining Am Cup car continues to circulate. The #166 Hägeli by T2 Racing Porsche had a long spell in the pits but is now back on-track in pursuit of class victory.