Philippe Gilbert (Quick-Step Floors) took a stunning solo win at the 2017 Tour of Flanders, riding everyone off his wheel with more than 55km still to race.
Gilbert held an advantage of over 50 seconds for much of the time he was away, often pushing it out to over a minute particularly when climbing.
Along with teammates Tom Boonen and Matteo Trentin, Gilbert agreed to go full on the Muur de Geraardsbergen and once they had got a group clear they pushed again on the Oude Kwaremont.
Gilbert looked back to find he was alone over the top and from there he continued alone all the way to the finish line.
Towards the end of the race, in the final 10km, Gilbert lost almost 30 seconds of his advantage in a matter of around 3km.
A group of three - Greg Van Averamet (BMC Racing), Niki Terpstra (Quick-Step Floors) and Dylan Van Baarle (Cannondale-Drapac) - brought the gap down to 36 seconds as they went under the 4km banner, which made Gilbert's win look far less certain.
At this point, Terpstra sat on the group having earlier contributed to the chase of his own teammate.
Van Avermaet was the best of the rest to take second place and the remainder of the finishers crossed the line in dribs and drabs.
Tour of Flanders 2017: How it happened
Gilbert was part of a select group that pushed on up the Muur de Geraardsbergen. Still a long way from the finish it was far from certain that this could be a winning move.
Team Sky had been setting the pace into the foot of the legendary climb, but a move from Boonen to the front shook things up.
Alexander Kristoff (Katusha-Alpecin) followed the Belgian and this move split the peloton. Gilbert was sitting in for a short period as he and his Quick-Step companions assessed the damage they'd done behind.
With 75km to go the Boonen group were just 1:50 behind the day's original break, but more importantly they were aleady a minute ahead of the Sagan group.
Gilbert then went solo up the Oude Kwaremont, extending his lead with ease. Behind there was a chasing group including Boonen.
That group contained a second Quick-Step rider - in addition to Boonen - in the shape of Matteo Trentin, along with Kristoff, Jasper Stuyven (Trek-Segafredo), Sep Vanmarcke (Cannondale-Drapac), Luke Rowe & Gianni Moscon (Team Sky), Maciej Bodnar (Bora-Hansgrohe), Arnaud Demare (FDJ), Sacha Modolo (UAE Emirates), Bryan Coquard & Sylvain Chavanel (Direct Energie) and Pieter Vanspeybrouck (Wanty Groupe Gobert).
This chase group managed to get back within 23 seconds of the lone leader before it all kicked off.
Vanmarcke lost his front wheel on a corner and took Rowe down with him. This split the group and sapped some of its chasing power.
Many of the riders disappeared out the back without much to say for themselves as the race got going and the attritional nature of the Ronde really took its toll.
Group two on the road, which contained some big guns, struggled to get within 50 seconds of Gilbert.
However, Sagan was able to chase back on with 48.4km to run and formed a key part of the group attempting to bring Gilbert back.
Sagan, Van Avermaet and John Degenkolb (Trek-Segafredo) were at the front on the final ascent of the Koppenberg as they tried to force the pace of their group.
Andre Greipel (Lotto-Soudal) was a bit further back at this point and later tried his luck off the front a couple of times, to no avail.
Turmoil came to the chase, firstly as Boonen had serious bike trouble at the foot of the Taaienberg and was forced to change his machine twice within about 15 metres.
The 37km left between him and the finish line was not enough distance for him to be a factor at the end.
At this point Sagan attacked forcing a huge effort from Van Avermaet and Oliver Naesen (AG2R La Mondiale) to get back to his wheel.
Van Baarle, Fabio Felline (Trek-Segafredo) and Yoann Offredo (Wanty Groupe Gobert) also made the junction and this group looked strong enough to catch the lone leader.
Hwoever, they leant on Sagan too much and the lack of full cooperation meant that Gilbert's lead remained comfortable.
What was arguably the most decisive incident of the day then occured on the final time up the Oude Kwaremont when Sagan, Van Averamet and Naesen were taken down.
It was unclear whether they caught the barrier as they rode in the gutter to the edge of the cobbles or if a spectator's jacket was to blame, but the result was the same: Sagan's chances were over.
Van Avermaet got back on his bike, back on the chase and took second on the line. Sagan had to wait an age for a new bike and his motivation had ebbed away.
Van Baarle was away on his own, behind Gilbert, after a move on the last time up the Paterberg but couldn't get within 48 seconds of the lone leader.
Van Avermaet also gave it his all on this climb and was followed by Terpstra, who until then had been in a group further back on the road.
Once these three joined together they had looked like a threat to Gilbert but with 53 seconds at the 10km to go banner he was able to stay away for an amazing win.
Earlier in the day, an original breakaway of eight riders was made up of: Julien Duval (AG2R La Mondiale), Oliviero Troia (UAE-Emirates), Edward Planckaert (Sport Vlaanderen-Baloise), Mark McNally (Wanty Groupe Gobert), Michael Goolaerts & Stef Van Zummeren (Vérandas Willems-Crelan), Julien Morice (Direct Energie) and Andre Looij (Roompot - Nederlandse Loterij).
This group of eight at one point counted an advantage of over 11 minutes but that was reduced to 5:50 with 100km to go, and on such a long day they were never going to stay away.
These escapees were all caught with 66km to the finish, and soon they were dropped by the Boonen group before the race really got going.