Home favourite Gianluca Brambilla seized the Giro d'Italia leader's jersey from Tom Dumoulin after a brilliant ride on stage eight in Umbria on Saturday.
Starting nearly two minutes behind Dutchman Dumoulin at the start of the 186km stage from Foligno to Arezzo, the Etixx Quick Step rider was rewarded for an audacious attack.
Part of an eleven-man breakaway group, the Italian surged away before the Alpe di Poti and powered to the line, one minute and six seconds ahead of compatriot Matteo Montaguti.
On a stage of searing pace, Dumoulin (Giant-Alpecin) had a torrid day and suffered badly on the dirt roads on the day's final climb, losing touch with a group that included pre-race favourites Vincenzo Nibali, Michel Landa and Alejandro Valverde.
Brambilla, who celebrated his first Grand Tour stage win, now leads by 23 seconds from Russian Ilnur Zakarin and will try and hang on to the pink jersey in Sunday's 40.5km individual time trial.
Nicholas Roche finished in 51st place, just over five minutes down on the leader and he sits just inside the top 30 4.34 down on Brambilla.
Philip Deignan lost 18 minutes on the stage and now sits in 99th place, nearly 39 minutes on the pink jersey.