Coming into the day with an eight second GC lead on Tadej Pogačar (UAE Emirates), van der Poel went on the attack early as he latched onto a very strong breakaway that formed with over 200 kilometres to go to the finish in Le Creusot, while Pogačar remained in the trailing peloton.
Locked in a battle with Wout van Aert (Jumbo-Visma) for the remainder of the stage, van der Poel dug deep in the finale to finish fourth overall behind Matej Mohoric (Bahrain Victorious) who soloed to victory a full minute and 20 seconds ahead of Jasper Stuyven (Trek-Segafredo) in second to complete a thrilling stage of attacking racing.
The champion effort extends van der Poel's lead in yellow to 30 seconds on van Aert, who moved into second as Pogačar dropped to fifth with a gap of 3 minutes and 43 seconds after being left to fend for himself in the peloton.
Absolutely spent after crossing the line but still wearing the maillot jaune, van der Poel admitted the stage forced him to give everything he had as he was forced to attack throughout.
“I’ve not seen this often in races like this, at 250 kilometres… especially not in a Grand Tour. I think everyone will sleep very well tonight.
“I was completely empty. I had to counter attack on Asgreen and Van Aert a couple times to keep the jersey and the group was watching me as well which is normal.
“It was very hard and took me to my limit, but I’m happy to keep the jersey for one more day, it was a difficult one."
As tomorrow's journey to Le Grand-Bornand takes the riders up and down three category 1 climbs including the brutal Col de la Colombière, van der Poel again conceded it would be difficult for him to hold on to yellow given his lack of climbing legs.
“You want to keep it as long as possible, but we’ll see how it goes tomorrow," he said.
"I’m a bit too heavy to get over the climbs. But we’ll see what's possible.”
The Tour de France continues with the first mountain stage of the race with the Col de la Colombière the final climb of the day before a descent in Grand Bornand. Watch the race from 20:30 AEST on SBS and SBS OnDemand, with the racing commencing on the SKODA Tour Tracker from 21:00 AEST.