Yellow jersey win at Criterium du Dauphine just a sign of things to come for Rohan Dennis

TO APPRECIATE what Rohan Dennis achieved at the Criterium du Dauphine overnight, look at the list of riders below him.

Australia's Rohan Dennis celebrates after putting on the yellow jersey.

TO APPRECIATE what Rohan Dennis has achieved in taking the yellow jersey at the Criterium du Dauphine overnight, look at the list of riders below him.

Chris Froome, Richie Porte, Michael Rogers, Geraint Thomas, Edvald Boasson Hagen, Sylvain Chavanel, Alberto Contador and Thomas Voeckler and that's only some.

Dennis, a 23-year-old from Vale Park in Adelaide's inner-north, in his rookie season as a professional cyclist is leading the best in the world after four stages of a crucial lead-in race for the Tour de France.

He took the yellow jersey with an outstanding performance in last night's 32km individual time trial in which he finished second behind world champion Tony Martin.

After the podium girls, the media interviews and the photos, Dennis went back to his team hotel in France and Tweeted his disbelief at what had just happened.

"No words could describe how happy I am right now," he wrote.

"But none of this would have been possible without the team protecting me on the climbs each day (in earlier stages)."

In reality, it should come as no surprise given Dennis' form in his first season for American team Garmin-Sharp.

He had to overcome a disastrous start when he broke his collarbone during preseason then missed the Tour Down Under in January with viral meningitis. But since then he has been nothing short of outstanding.

At the Tour of Romandie in April he was ninth in the final stage time trial over 18.7km then made a huge statement at the Tour of California in May when he was third in the 31.6km individual time trial.

He is clearly transferring his outstanding pursuiting background from the track onto the roads of Europe and what makes him such a promising prospect is the fact that he can also climb.

The question tonight as the peloton tackles a mountainous 139km stage five from Gresy-sur-Aix to Valmorel will be how Dennis' climbing compares to the elite like Froome, Porte and Contador.

It may boil down to how much he has left in the tank after emptying himself to finish second in last night's time trial, midway through a big season as a neo-pro.

Regardless of what happens, a beaming Dennis on the podium in yellow is surely a sign of things to come with his career only just beginning.

Immediately after Wednesday night's time trial, Dennis was asked by a television reporter whether he would be riding the Tour de France in three weeks' time.

"It's a big ask," Dennis said.

That wasn't a yes, but it wasn't a no either and the prospect of sending him to Corsica on June 29 must be more tempting to team boss Jonathan Vaughters and Co by the day.