Fernando Gaviria takes second stage win
The Colombian holds off Peter Sagan and Andre Greipel in a thrilling finish
BMC's Greg van Avermaet retains yellow jersey
That's it for this live text.
The race report is building here.
The Bespoke podcast looking back at stage four will be available here shortly.
And if you're wondering what Mark Cavendish's next hope of a stage win is - why not read his stage-by-stage guide here?
We'll be back with live coverage of stage five tomorrow as the race goes over hilly terrain for the first time.
Cheers!
Mark Cavendish, speaking to ITV4 while holding his baby son: "The team were brilliant for the final kilometres. We executed what we wanted to - we knew we had to take it on even though it was a headwind.
"But with that block headwind, once you're not on a wheel then you have to put in double the effort.
"Kragh Anderson pushed me off my lead-out man Mark Renshaw's wheel, I thought the left side would be closed so went right and was back on Renshaw but then it opened up and Quick-Step went through.
"I was then blocked by my own lead-out man effectively but it was my own fault - I shouldn't have been there."
"Quick-Step are hard to beat anyway - it's another stage win for them and I'm left holding the baby."
Rigoberto Uran was able to catch back on despite being held up by that late crash.
The Colombian remains in 10th place on general classification, 35 seconds back.
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Tiesj Benoot of Lotto Soudal has just come across the line in last with a bloodied face. The Belgian fell heavily in that late crash.
Chris Froome and Adam Yates finished safely in the main bunch.
Another GC rider, Ilnur Zakarin of Katusha, was caught out though after that late crash and looks to be the big loser from the overall contenders.
Watching replays of the finish, Mark Cavendish just didn't have the legs to contest the finale despite being well-positioned with 800m to go.
He gets swamped as Greipel, Gaviria and Sagan surged clear.
The Briton is then also cut up by Dylan Groenewegen and raises his hand in protest. I'm not sure he could've got there even without that though.
BMC's Greg van Avermaet avoided that late crash that split the bunch and rolled over the line safely in front group.
The Belgian keeps the leader's yellow jersey.
Fernando Gaviria edges it on the line, holding off world champion Peter Sagan, who takes second, with Andre Greipel third.
The German led it out but could not maintain his kick for long enough to deny the rapid Gaviria, while Sagan - ever the opportunist - nicked second too.
Confirmation - the Colombian sprinter Fernando Gaviria win his second stage of the 2018 Tour de France in a thrilling finish in Sarzeau.
Photo finish! I think Gaviria gets it.
Here comes Andre Greipel!
Gaviria and Sagan in pursuit.
Cavendish out of it.
Gaviria and Sagan in pole position. Cavendish caught slightly back.
It's a brutal long drag to the line, Dimension Data still on the front. Now Bora come through and Quick-Step are up there.
Mark Cavendish is sat in fifth place as Dimension Data string it out on the left.
Under the flamme rouge - just 1km to go.
Just 10 seconds now for the break out front. The catch should be made soon and then a frantic final 1km to set up the bunch sprint.
Rob Hayles
Ex-GB cyclist on BBC Radio 5 live, in France
It's an advantage for the peloton to be able to see the breakaway on this long, straight run-in.
Just 20 seconds now for the four-man breakaway.
Team Sky come to the front to keep Chris Froome safe into the final 3km.