The race shortly after entered the cobbles and soon opened up. Several crashes firstly took out some riders from contention such as Peter Sagan, whilst splits had to often be undone due to the natural difficulty and characteristics of the cobbled sectors, mechanicals were also frequent but allowed for recovery at this time of the race.
With 103 kilometers the race opened up. Wout van Aert launched an attack, followed by his teammate Christophe Laporte, Mathieu van der Poel, John Degenkolb and Stefan Küng. The quintet quickly rode away from the peloton and caught up with the survivors of the breakaway at the Trouée d'Arenberg. There Laporte suffered a puncture and was dropped from the front, as in the peloton a mass crash took out several contenders out of the race such as Dylan van Baarle and Kasper Asgreen.
Other riders managed to shortly after bridge across, including Mads Pedersen, Filippo Ganna, Max Walscheid and Alpecin duo Jasper Philipsen and Gianni Vermeersch. Van der Poel kept putting on the pressure, attacking with 51 kilometers to go with a response from Degenkolb and van Aert, but the trio were caught after by a reduced group. Shortly after he attacked again at Mons-en-Pevele but to no real effect.
7 riders powered through into the final sectors. Van der Poel, Philipsen, Van Aert, Küng, Pedersen, Ganna and Degenkolb. Carrefour de l'Arbre seemed to be the critical moment and once in the sector Degenkolb crashed after clashing with the Alpecin duo, whilst Wout van Aert attacked off the front. Soon the Jumbo-Visma rider saw his race turned upside down however as he punctured still in the cobbles.
Van der Poel managed to respond, and then rode solo off the front whilst the remaining riders connected behind, putting on a not-so-organized chase as Philipsen looked to disrupt. Van Aert attacked in the final sector to Hem as the gap hovered around 30 seconds, but taking Pedersen and Philipsen with him, collaboration remained complicated. Van der Poel was riding solo to the victory.
Van Aert managed to drop the Dane, but Jasper Philipsen sprinted to second to complete a perfect one-two. Van Aert completed the podium, Pedersen, Küng and Ganna followed.