Liquigas' Franco Pellizotti took victory on stage 16 of the Giro d'Italia, a mountain time-trial finishing at the Plan de Corones ski station.

The 30-year-old from Udine powered up the vertiginous final kilometre to take his second stage win in his home tour.

Astana's Alberto Contador finished in fourth position to increase his lead in the general classification to 41 seconds over his main rival Riccardo Ricco.

"My objective was to keep the pink jersey and perhaps gain a few seconds, so I'm happy with the result," Contador said.

"I went to see the course this morning and rode up the final dirt section. I'm glad I did because it made me realise I needed a bigger gear.

"I used a 34x30 and I think it helped me keep the pink jersey because my back wheel was slipping on the steepest parts of the climb."

Of the earlier starters, CSF's Julio Alberto Perez Cuapio clocked the fastest time, covering the tough 12.9-kilometre course in 43'22". His time was beaten by Caisse d'Epargne's Jose Rujano, while Andreas Klöden, one of the pre-race favourites, rolled in well off the pace.

Emanuele Sella further highlighted his quality by chopping a huge 43 seconds off Perez Cuapio's, and must have thought he was on for a stunning third consecutive stage win, until Pellizotti hauled himself across the line six seconds quicker.

Denis Menchov and Danilo di Luca lost further precious time on the GC, finishing 1'49" and 1'45" down on Pellizotti respectively.

Diquigiovanni's 37-year-old Gilberto Simoni fared better, limiting his losses to just 17 seconds on his compatriot to finish third.

Ricco rolled across the line 30 seconds off the pace, before Contador powered up the final kilometre to secure fourth place on the stage, and strengthen his hold on the pink jersey ahead of Tuesday's rest day.

He now lies 41 seconds ahead of Ricco at the top of the general classification with five stages remaining, including two mountain stages and the final time-trial into Milan.

"Denis Menchov, Marzio Bruseghin and Danilo Di Luca have lost some time but the other time gaps were minimal," he continued.

"There are probably now five or six riders who can win the Giro. Ricco has confirmed that he's very strong and he and Gilberto Simoni are my main rivals.

"I'm confident for the final stages. The most difficult moment for me was the start and the last three stages we've done in the Dolomites.

"My form is improving or at least staying the same, so I don't think my rivals can hurt me that much."

Michael FitzGerald / Eurosport