A former teammate of Cadel Evans was central to his loss of vital time to race leader Vincenzo Nibali in the Alps on the Giro d'Italia.

Italian Mauro Santambrogio (Fantini Vini), who rode with Evans on BMC in the 2010 Tour de France, won the Giro's 14th stage from Cervere to Bardonecchia.

With Evans (BMC) and Santambrogio racing on rival teams, the harsh reality of their loyalty was made clear for all to see on Saturday when Santambrogio clearly worked with fellow Italian Nibali (Astana) in an attack that dropped Evans.

There was no illicit captivity. Both riders race for opposite teams driven by different ambitions. But when Nibali attacked with 1.8 kilometres to go on the steep 7km climb up to Bardonecchia to trigger a chase by Evans and Santambrogio, he and Nibali naturally worked together.

Santambrogio later said he was keen for the stage win and the union paid dividends for Nibali, who took second place and a 12-second time bonus for his effort.

For Sunday's 15th stage from Cesana Torinese to the Col du Galibier - cut to 146.5km due to snow on the finishing climb - Nibali was first overall, one minute 26 seconds up on Evans and 2:46s up on Colombian Rigoberto Uran (Sky).