Ex-Formula 1 racer Nasr posted a best time of 2m04.443s at the wheel of the #5 Penske Oreca 07-Gibson on Friday morning to make it a second session in a row topped outright by an LMP2 car.
The Brazilian’s benchmark was more than a second faster than the time with which WRT’s Robin Frijns paced first practice on Thursday.
Making it a one-two on the overall leaderboard for US entrants was Glickenhaus driver Olivier Pla, who topped the four-car Hypercar division with a 2m04.464s in the boutique marque’s solo 007 LMH.
Third-fastest was the best of the two Toyota GR010 Hybrids, the #8 car, which topped the times early on with a 2m04.692s in the hands of Brendon Hartley – 0.249s off the pace set by Nasr.
The sister #7 Toyota was sixth-fastest with Jose Maria Lopez setting a 2m05.128s.
Splitting the two Japanese cars were the second- and third-fastest LMP2 runners, with the #23 United Autosports Oreca of Oliver Jarvis leading the Prema machine of Louis Deletraz.
United’s second car, driven by Filipe Albuquerque, was fourth in the LMP2 standings and seventh overall, followed by the two JOTA Orecas, led by the #38 machine with Will Stevens driving.
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The fourth and final hypercar entry, the Alpine A480 grandfathered LMP1 car, was 10th overall and a little more than a second off the pace in the hands of Andre Negrao.
Leading the way in the LMP2 Pro/Am subclass was the AF Corse Oreca of Alessio Rovera.
Porsche once again topped the times in the GTE Pro division, as Michael Christensen narrowly improved on the best time set in FP1 with a best effort of 2m14.366s in the #92 911 RSR-19.
Ferrari this time ended up second and third in class with its AF Corse-run 488 GTE Evos, James Calado putting the #51 machine just a tenth of a second ahead of Antonio Fuoco in the #52 car.
Corvette Racing’s solo C8.R was fifth in class with Spa debutant Tommy Milner at the wheel.
An early lap of 2m15.604s from Matteo Cairoli was enough to top the GTE Am class for the Project 1 Porsche squad ahead of Seb Priaulx in the Dempsey-Proton Racing Porsche.
The session was halted with around seven minutes remaining owing to debris on track.
One more WEC practice session takes place at Spa on Friday afternoon at 2pm local time ahead of qualifying at 6.20pm.