Team Sky's Richie Porte has won Stage Four of the Paris-Nice race.
Michael Matthews was the new leader of this 204km stage from Varennes-sur-Allier to Croix de Chaubouret which was a stage of eight climbs and two sprints and saw 157 riders set off at 10.21 local time.
Thomas de Gendt of Lotto Soudal and Antoine Duchesne of Europcar were the first to attack and were joined after five kilometres by Chris Anker Sorensen of Tinkoff Saxo.
The trio were quickly into a lead of 4.10 which was 7.15 when they crested the first climb of the day - the category three Cote de Cheval Rigon which saw Thomas de Gendt take the four points.
De Gendt took another four points on the Col du Beau Louis after 54kms as the trio extended their lead to eight minutes.
However, when it came to the first intermediate sprint after 59.5kms, it was Antoine Duchesne who took the three points and three seconds bonification points.
Astana sent two riders up the road and the gap started to drop as the average speed for the third hour went up to 42.3 kph for an overall speed so far of 39.3 kph.
With 57.3kms to go and after de Gendt had taken the four points on the category three -Cote de Saint-Heand, the three up front had a lead of 4.45.
As Duchesne dropped back, de Gendt took the seven points on the category two - Cote de la Gimond.
The gap started to fall and de Gendt and Sorensen were 3.30 ahead thanks to work from AG2R who had Samuel Dumoulin, Johan Van Summeren and Jan Bakelants chasing after De Gendt and Sorensen who were 1.40 ahead as they went over the second category Cote la Gachet which meant another seven more points for the Lotto Soudal rider.
De Gendt took another four points on Cote de la Croix Blanche on the penulimate climb as their lead dropped to 1.15 and was a minute as they went into the last twenty kilometres of the stage.
The second intermediate sprint in St Chamond was held in memory of Kazakh Andrei Kivilev who was killed in the 2003 Paris-Nice and a death which made crash helmets mandatory. Sorensen took the sprint just ahead of de Gendt with Phillipe Gilbert, who had been in the points for most of the climbs to try and keep him in the polka dot jersey, taking the third point and one second bonus.
With thirteen kilometres left, the great work by de Gendt and Sorensen was over as they were brought to heel by a peloton trying to set themselves up for the end of the stage which saw a ten kilometre climb up to the Croix de Chaubouret.
There was a crash with Warren Barguil of Team Giant Alpecin staying on the deck as the climb started.
Rafal Majka was soon dropped out the back of the peloton before Paolo Tiralongo of Astana launched an attack with 8.7kms left.
Through the town and over the cobbles on a sunny afternoon and Tiralongo was thirty metres ahead before being caught by Team Sky two kilometres later.
With race leader Michael Matthews struggling down the road and his chance of staying in the race lead looking to be over, Irishman Nicholas Roche of Team Sky working for Richie Porte took to the front.
Riders including Tony Martin and British rider Simon Yates were being dropped all over the road.Roche continued to put in the work which saw the lead group reduce and allowed Geraint Thomas to attack with 2.7kms to go with Jakub Fuglsang of Astana in his wheel, followed by Spillak.
The attacks continued with Tejey Van Garderen and Richie Porte trying to bring back this trio. A Movistar rider in Fernandez crashed into the American who kept going as Thomas led on the front on a road which has snow on the side in parts.
Under the flam rouge and Porte's group had caught up to Thomas. The Team Sky pair went with seven hundred metres to go.
There was no-one behind them and Porte took the win in 5.18.39, punching the air as did Geraint Thomas who finished second just behind him. Third was Michael Kwiatkowski, followed by Van Garderen, Fuglsang, Gallopin, Costa, Inxausti, Macahado and Valls.
Michael Kwiatkowski is back in the leaders yellow jersey.