Vanthoor led the first qualifying session of the most prestigious World Endurance Championship round with a lap of 3m24.465s, nearly two tenths faster than Cadillac's Sebastien Bourdais.
Vanthoor was only 16th quickest in the short first sector, but he was timed in 1m33.097s in the last one, with Cadillac's Alex Lynn and Bourdais respectively 0.149s and 0.418s slower. Ferrari's Antonio Fuoco, third fastest overall, was 0.462s slower in sector three.
"We were not expecting this," Vosse admitted. "We did not really know what to expect, but we could see that Dries' last sector made a huge difference in particular.
"And to make such a difference in the third sector, you need to have a good car, but you need to be well equipped!" he added, meaning that Vanthoor needed some guts there.
"Well, maybe the red flag helped us at the end, but who knows? I think, based on his last sector, based on the gap he was creating [for his next lap]."
This is a welcome result for BMW's WRT factory squad, which has failed to finish a race in the Hypercar's class top five so far in 2024 – with the top 10 eluding Vanthoor and his #15 entry team-mates Raffaele Marciello and Marco Wittmann.
"The BMW had almost never done so well, that's the least one can say," Vosse exclaimed. "But we did know – we saw at Imola, at Spa, that we were making progress. We did some testing in the meantime, we found some small things again.
"This was on one lap, now we need to look at it on the long term, over a 24-hour race that will be tricky – as the weather seems to show."
Now, Vosse is not ruling out Vanthoor taking a shock pole position for the legendary French race: "Why not? If he did it today… And he was improving! In the first two sectors, he was five tenths up on his time, so why not?"
