Rubiano climbs to the fore
Colombian rider Miguel ngel Rubiano won the sixth stage of the Giro d'Italia as Adriano Malori took the overall lead.
Rubiano (Androni Giocattoli-Venezuela) claimed an impressive breakaway victory as the race hit the mountains.
Rubiano had gone away early in a big escape group and left what remained of his fellow escapees behind on the brutal ramps of the third category Montegranaro climb, around 40 kilometres from home in the 210km route from Urbino.
He built on his advantage on the run to the finish at Porto Sant'Elpidio, comfortably holding off the four-man chase group to cross the line one minute and 10 seconds ahead of Adriano Malori (Lampre-ISD) and Michal Golas (Omega Pharma-QuickStep).
The 12 seconds bonus for second place proved crucial for Italy's Malori as it put him in the leader's maglia rosa, 15 seconds in front of Golas, with Ryder Hesjedal (Garmin-Barracuda) a further two seconds back.
Hesjedal was in the main pack which finished 1:51 behind but his team-mate Ramunas Navardauskas, leader at the start of the stage, endured a tough day as he came home well adrift.
Rubiano's efforts also saw him top the mountain classification and he admitted that had been his initial objective, saying: "I felt good the entire stage. The aim was to go for the mountain's jersey first of all but then I pressed on afterwards and it's fantastic to get the win."
The toughest day of the Giro so far, stage six saw the riders challenged constantly with an undulating parcours.
Ahead of the 20km marker a significant break went clear, 15 riders pushing onwards to build up an advantage of 8:36 before the terrain caused the break to fracture.
The gravel 'strade bianche' roads made their third consectutive appearance in the race and the ascent of the second category Passo della Cappella thinned out the bunch significantly.
Among those struggling were Navardauskas who was repeatedly forced to chase back on during the day, finally dropped on the Montegranaro after a gutsy ride.
With a number of big teams represented out front Liquigas-Cannondale took up the pace-setting duties on the front over some tough terrain - the stage profile on paper belying just how difficult the climbs were.
The day also saw a number of high profile abandonments with Tyler Farrar (Garmin-Barracuda) and Thor Hushovd (BMC Racing) leaving the race, the former following a crash.