A storming victory in the third-stage 18.2-kilometre team time trial in Carmarthenshire saw INEOS Grenadiers cement their lead in the team classification at their home-country race and catapult Ethan Hayter and Rohan Dennis into first and second position overall.

Monaco-based Tasmanian Porte said his Aussie compatriot was pivotal to securing the 17-second stage win.

"It's fantastic with Ethan taking the (leader's) jersey and hats off to Rohan Dennis there who really got us across the line and was incredibly strong," he said.

The 36-year-old father-of-two added: "We're motivated, (it's our) home race and great result.

"To win the stage is a great satisfaction, it's nice to race in Wales and we'll try and defend this jersey. It's not going to be easy but we have a solid team here to do something about it."

Young Brit Hayter, who also leads the points classification, has a six-second overall advantage over Dennis with Belgian Wout Van Aert (Jumbo-Visma) a further 10 seconds down in third.

Five stages remain with the tour finishing in Aberdeen on Sunday.

Porte leapt up 30 places to be 19^th overall, 1:28 off the pace. The race is his first competition since coming 27^th in the time trial and 48^th in the road race at the Tokyo Olympics a week after finishing 38^th in his 11^th Tour de France.