Team Sky threw their support behind Richie Porte on the longest stage of the Giro d'Italia to maintain third place overall.

The team surrounded the Tasmanian with numbers on the tricky run into Fiuggi as day seven came to a nervy conclusion after over seven hours in the saddle.

Powerful stints on the front from Vasil Kiryienka helped move the team forward, with Porte always in a prominent position to remain 20 seconds back on the maglia rosa after a week of racing.

It was also a good day for Elia Viviani who picked up points at both intermediate sprints during the stage to move back into the red jersey by three points over Andre Greipel (Lotto Soudal).

Diego Ulissi (Lampre-Merida) was able to grind out the stage win on the uphill sprint, taking an emotional victory ahead of Juan Jose Lobato (Movistar) and Simon Gerrans (Orica-GreenEdge).

Leader Alberto Contador (Tinkoff-Saxo) battled on without time-loss after dislocating his shoulder in a crash at the end of Thursday's stage. The Spaniard had endure the longest stage of this year's race, and the longest in the event since 1989, at 264km.

"I was able to pick up a few points during the stage at the sprints and it's great to be back in the red jersey," said Viviani after coming off the podium.

"It was a tough and long stage and I understood after the second intermediate sprint that I wasn't on my best day and I wouldn't finish in the front group."

Racing into headwinds for much of the marathon stage resulted in a slow average speed of 35km/h as the peloton gradually clawed back the day's break.

Kanstantsin Siutsou moved up to the front in the closing stages after being caught up in a light crash with 24km to go. Leopold Konig, Salvatore Puccio, Sebastian Henao, Kiryienka and Mikel Nieve were all in the front group, with Bernhard Eisel pulling off after great positioning work ahead of the final climb.