The 222 kilometre 16th stage tasked the peloton with crucial climbs of the Mortirolo, the Stelvio and the Umbrailpass, following yesterday’s rest day.

Race leader Dumoulin stayed in contact with his general classification rivals during the first two major ascents of the stage.

The day would take a dramatic turn when the Dutchman leapt from his bike as they approached the final climb of the day, with the Sunweb rider requiring a toilet break.

The general classification contenders briefly slowed, as Dumoulin had when Colombia’s Nairo Quintana suffered a crash earlier in the race.

Russia’s Ilnur Zakarin eventually launched an attack with the pace then increased further by Quintana.

Nibali and fellow Italian Domenico Pozzovivo joined the pair, with Dumoulin then forced to set off in pursuit.

He was forced to attempt to limit his losses, having fallen one minute and 30sec behind, as attacks began at the front of the race.

Nibali eventually claimed the stage victory in a time of 6 hours, 24min and 22sec, catching Team Sky’s Mikel Landa.

The Spaniard had been the last rider caught from the breakaway and he ended with the same time as Nibali, who claimed Italy’s first stage win of this year’s race.

Quintana would cross just 12sec behind and would make large inroads in Dumoulin’s lead, as the Dutchman ended 2:18 behind the stage winner.

“I just had some problems,” said Dumoulin.

“I started to feel it in the downhill of the Stelvio and I had to stop.

“Back on the bike I decided to fight and draw conclusions after the finish.

“I'm still in the Maglia Rosa but I'm above all very disappointed.”

Dumoulin’s race lead is now down to just 31sec from Quintana, having held a 2:41 advantage at the start of the day.

Defending champion Nibali is 1:12 off the race lead, while France’s Thibaut Pinot is 2:38 down.

The International Cycling Union (UCI) WorldTour race continues tomorrow with a 219km stage from Tirano to Canazei.