Eurosport - Sat, 22 May 16:17:00 2010
Victory for the Italian was the third successive stage win for a home rider, as Liquigas enjoyed a one-two with Ivan Basso, another Italian, claiming second.
Basso, along with fellow overall contenders Michele Scarponi (Diquigiovanni-Androni) and Cadel Evans (BMC Racing Team), finished 23 seconds behind Nibali on the 201km ride from Ferrara to Asolo, which took in the gruelling climb and long descent of the Monte Grappa.
Former race leader Alexandre Vinokourov of Astana came home alone in fifth, a further 71 seconds back.
Behind the Kazakh rider was a nine-man group including Arroyo, who finished 2:25 behind Nibali, and that performance was good enough to depose Australian Richie Porte (Saxo Bank), in the next group on the road, as overall race leader.
Arroyo now holds a 39 second advantage over Porte with Cervelo's Tondo in third, 2:12 behind his Spanish compatriot.
Robert Kiserlovski, Linus Gerdemann, Sastre and Wiggins - also members of the break on Wednesday that gained 12 minutes on most of the pre-race favourites - follow in the overall standings with Nibali, Vinokourov and Evans completing the top 10. Basso and Scarponi follow with the top 12 riders separated by less than 10 minutes with the toughest week of the race yet to come.
An early breakaway group consisting of William Bonnet (Bbox), Damien Monier (Cofidis), Alessandro Bisolti (Colnago), Steven Cummings (Sky), Markus Eibegger (Footon) and Filippo Pozzato (Katusha) set the pace before Bisolti broke away at the foot of Monte Grappa.
Cummings went with the Italian, but soon disappeared with team-mate Wiggins taking his place.
But with an average gradient of nine per cent the Monte Grappa, visited four times before on the Giro but not since 1982, represented a tough ascent and before long both riders had also succumbed.
Nibali took advantage, reaching the summit in a group with Basso, Scarponi and Evans before moving ahead with some fearless riding on the descent - especially considering the short shower that had fallen.
Vinokourov also pushed himself to the limits on the way down the mountain, but ultimately he was unable to make an impression on the leaders.
Nibali's victory saw him revive his bid for this year's Giro crown.
"It's a beautiful day," Nibali, who led for three stages earlier in the race, told Rai television.
"I didn't think I was going to make it because I had a long way (to defend the lead). I had to pull off a beastly effort."
Giro d’Italia: Sunday: LIVE on the Eurosport Player from 1.30pm. Highlights on British Eurosport (Sky 410 / Virgin 521) at 8.05pm.