Porte, who rides for Ineos Grenadiers, finished eighth at the end of the 147 kilometres route from La Léchère-les-Bains to Les Gets on a stage won by Ukraine's Mark Padun.

The Australian needed the support of team mate and 2018 Tour de France winner Geraint Thomas to seal his maiden win in the event following two previous runner-up results.

Thomas endured a tough stage as he crashed 7.7km from home before remounting to finish third and help Porte's pursuit of the general classification title.

Padun, of Bahrain Victorious, crossed the line in four hours 6min 49sec to clinch his second consecutive stage victory.

"This race, having been second here twice and one year losing second in the last kilometre, to finally win it I'm just over the moon," said Porte.

"All the sacrifices, time away from my wife and two kids, is worth it. 

"This team Ineos Grenadiers were just absolutely brilliant today.

"I know the descent of the Joux Plane well and we've done it many, many times, so decided to do it at my own pace. 

"When I saw Geraint crash it wasn't ideal for the last six kilometres. 

"He has some pretty bad road rash, but he'll be tip top for the Tour."

The Critérium du Dauphiné is viewed as a key build-up event for the Tour de France, which is scheduled to begin on June 26.