Matej Mohoric celebrated a solo victory as the longest stage of the Tour de France in 21 years delivered an unexpected shake-up of the fight for yellow.
Primoz Roglic could be out of the game after being dropped late on the 249km stage from Vierzon to Le Creusot, while defending champion Tadej Pogacar was left surprisingly exposed after a 29-strong breakaway stretched his UAE Team Emirates squad to the limit.
That breakaway included race leader Mathieu van der Poel, who was able to defend the yellow jersey for one more day and unexpectedly stretch his advantage as with the peloton distanced.
Dan Martin finished 66th on the stage, over nine minutes behind the winner. Martin is 63rd overall, 20:03mins off the yellow jersey.
At the end of a frantic day, Van der Poel had seen what had been an eight-second lead over Pogacar in the general classification become a 30-second lead over Van Aert.
Kasper Asgreen and Mohoric moved up to third and fourth respectively, with Pogacar now fifth, three minutes and 43 seconds down.
The Slovenian remains the best-placed of the overall contenders for glory in Paris, but there are huge question marks over his supporting cast after a brutal day.
Richard Carapaz had tried a late attack out of the peloton, going forward just as his Ineos Grenadiers team-mate Geraint Thomas went out the back, though there was a regrouping before the finish with no major time gaps between them.
