The Belgian rider appears to have taken a corner too wide, and upon correction was forced to brake hard to avoid other riders who had bunched up in the bend. As a result the BMC Racing Classics man can be seen flipping all the way over his handlebars.
After staying down for some time, van Avermaet is able to get up and walk along the roadside in search of a replacement wheel, which hopefully means he was not badly injured in the incident. Fabian Cancellara was not as lucky when he crashed earlier in the stage, and he will now miss the remaining Classics due to back and wrist injuries.
At this stage in the race, the peloton was already split into groups on the road, and what proved to be the decisive move of the day was forming. Geraint Thomas (Sky), Zdenek Stybar (Etixx – Quick-Step) and Peter Sagan (Tinkoff-Saxo) were already hitting off the front of the main group.
This move survived and the three riders worked well together to increase their advantage. With about 4km to go, Thomas attacked and soon had a gap. Stybar reacted, but late, and the move appeared to be too much for Sagan who fell back and was later passed by the chasing group before the finish. Thomas took a fine solo win to better his third place finish last year.