Aru emulates fellow Italian Vincenzo Nibali by winning fifth stage, but he would prefer to enjoy moment after tough times recently.
Tour de France: Aru 'to take it day by day' after winning Stage 5 as Froome wears yellow jersey
Fabio Aru emulated compatriot Vincenzo Nibali in winning the fifth stage of the Tour de France on Wednesday as reigning champion Chris Froome took over the race lead.
Italian Aru won the 160.5-kilometre stage that finished on the La Planche des Belles Filles climb, where Nibali won three years ago before going on to claim Tour victory.
Froome came home third behind Ireland's Dan Martin in second, and he took over the yellow jersey from Sky teammate Geraint Thomas.
Aru launced his attack with 2.4km left and finished 16 seconds clear of Martin. With a 10-second time bonus on the line, he moved up to third overall, at just 14 seconds behind Froome.
But more importantly, the 2015 Vuelta a Espana winner made a statement that he is a genuine challenger to end Froome's Tour reign.
Having previously won stages at the Giro d'Italia and Vuelta, this completed a Grand Tour stage sweep for Aru.
"First of all I'm going to enjoy this moment because I had a great spring and won the Italian title but before that I had a tough time," said Aru, who had to pull out of May's Giro due to injury.
"It's a difficult race and the opposition is very tough. I'd prefer to take it day by day because I didn't expect to compete at the Tour.
"My goal was the Giro but unfortunately I was injured."
Briton Froome came home 20 seconds behind the winner, with Australia's Richie Porte just behind him, but Colombian Nairo Quintana struggled and lost 14 seconds to Froome.
"It's amazing for me to be back in yellow but having said that the race is far from over," warned Froome.
"(Aru) showed already in the (Criterium du) Dauphine he was in great form, today he just confirmed that.
"Fabio's going to have to be one of the guys we keep an eye on in the next couple of weeks."
Last year's runner up, Romain Bardet came home fifth at 24sec behind Aru, to now sit seventh overall at 47sec.
Thomas, who started the day 12 seconds clear, dropped to second at 12sec behind his team leader.
But at the end of the first mountain summit finish of this year's race, the overall standings took on a familiar look as the overall contenders flexed their muscles for the first time.
The top 10 are now separated by one minute with all the big guns in there, including two-time former winner Alberto Contador, now eighth at 52sec.
Porte moved up to fifth at 39sec, with Quintana ninth at 54sec.