The Astana-Premier Tech rider finished the 16.4-kilometre time trial on rolling terrain in 21mins 36secs, beating Spanish team mate Ion Izaguirre Insausti’s mark by eight seconds to secure the win.

Pöstlberger of Bora-Hansgrohe placed ninth but it proved to be enough to clinch the top spot with Lutsenko exactly one second behind at the halfway stage of the International Cycling Union WorldTour race.

"It’s perhaps a surprise victory, but I gave it my all and we’ve been working a lot on the time-trial bike," said Lutsenko.

"I want to thank the team, who gave me lots of strength and motivation.

"It was a perfect route for me, going up and down all the time.

"I’m one second behind the yellow and blue jersey and the Dauphiné isn’t over yet.

"Tomorrow is a good stage for me and there are plenty of mountains this weekend. 

"I’m going to try my luck tomorrow.

"After that, the Tour de France will be the main event, but I’m also aiming for the Olympic Games and this victory will give me lots of confidence, even if I’m taking it one stage at a time."

Denmark’s Kasper Asgreen of Deceuninck-Quick Step, finished third, nine seconds behind Lutsenko - the same amount of time he trails Pöstlberger by in the general classification race.

Dutch rider Wilco Kelderman of Bora-Hansgrohe and Belgium’s Ilan van Wilder of Team DSM also remain in contention after finishing fourth and fifth respectively on stage four.

"I’m very happy," said van Wilder.

"After my time-trial in Romandie, I felt confident to do good. I felt good today.

"The course suited me.

"The uphill sectors were good for me, I could push a lot of power and then rest on the downhills.

"I think I did a good TT. I’ll try to do my best every day and see how far I perform in the mountains."

Competition is set to continue tomorrow with the 175.4km flat stage from Saint-Chamond to Saint-Vallier.