Fabio Aru in pink after Sacha Modolo wins chaotic finale

It was another tumultuous day on this increasingly intriguing Giro, with Contador losing a leader’s jersey during a Grand Tour for the first time in his long illustrious career.

The 32-year-old rider from Tinkoff-Saxo was brought down in a mass pile-up just outside the three-kilometre limit and crossed the finish line in Jesolo 40 seconds down on stage winner Modolo.

Modolo outsprinted fellow Italians Giacomo Nizzolo (Trek Factory Racing) and Elia Viviani (Team Sky) at the end of a rain-soaked 147km stage in the Veneto to secure his team's third stage win in the 98th edition of the race.

With Astana’s Aru safely avoiding the incident, the young Italian secured the first maglia rosa of his career – a day after showing his first signs of vulnerability and being dropped by his big rival on a decisive climb.

Aru crossed the line in a group four seconds down on Modolo and now leads the overall standings by 19 seconds over Contador, with team-mate Mikel Landa in third place at 1:15.

There was more disappointment for Australia’s Richie Porte, however, when the Team Sky rider trickled across the line more than two minutes down to plummet down the overall standings to cap a miserable second week of racing.

CONTADOR UPBEAT: "I was really well placed and I could see the crash coming,” Contador, who dislocated his shoulder in a similar incident in the Giro’s opening week, told Eurosport. "It was just ahead of the three-kilometre mark. First of all I checked I was ok and then it was my priority to get a new bike – any bike.”

Luckily for Contador, team-mate Chris Juul-Jensen was on call to hand over his steed – but despite digging deep, Contador could not avoid conceding 36 seconds to Aru ahead of Saturday’s all-important individual time trial.

"The loss is not too bad. I just hope I’m ok and I can make the time back. Of course, the shoulder still hurts, but I want to keep positive. I’ll put some ice on it tonight and make sure I’m all right for tomorrow.”

ARU ALL SMILES: His face was a picture of pain after he toiled up Monte Berico at the conclusion of Thursday’s stage 12, where Contador increased his lead by 14 seconds after a timely dig towards the finish.

But 24 hours makes all the difference in cycling – and the 24-year-old Sardinian was all smiles after unexpectedly picking up a maiden pink jersey beside the lagoons of Venice.

"Yesterday was a hard day. I didn’t eat enough and paid for it at the finish,” Aru told Eurosport. "Today I wanted to keep near the front and avoid any problems so I must thank my team-mates for looking after me.

"It’s a really important day tomorrow because it’s a long time trial.” Given Contador’s superiority in the discipline, everyone will expect the Spaniard to regain the race lead after the 60km race against the clock from Treviso to Valdobbiadene – but nothing is guaranteed in this compelling Giro.

LAMPRE TRIPLE: Modolo, 27, wrote the latest chapter in Lampre-Merida’s wonderful Giro d’Italia with an impressive kick on the final straight in Jesolo. Despite losing lead-out man Roberto Ferrari in the day’s main flashpoint, Modolo benefited from the help of two team-mates to deliver the goods.

Modolo pipped Nizzolo and Viviani in an all-Italian top three to secure Lampre’s third scalp of the race following earlier victories for Jan Polanc and Diego Ulissi. Just 14 riders finished in the front group after the devastation caused by the crash.

Earlier in the day, a three-man break of Rick Zabel (BMC), Marco Frapporti (Androni Sidermec) and Jerome Pineau (IAM Cycling) had ridden ahead of the pack with a maximum lead of just over two minutes after breaking clear in the fourth kilometre of the pan-flat stage from Montecchio Maggiore.

With the rain still pounding down, the leading trio were swept up with just under 18km remaining as the teams of the main sprinters and GC favourites jostled for positioning ahead of what was expected to be a nervous finale.

PORTE PAIN: The crash occurred with 3.2km remaining as riders were negotiating a technical part of the race that involved numerous roundabouts and pieces of road furniture.

Ironically enough, the actual incident happened on a straight stretch of road after a rider was forced onto the grass verge, skidded, touched wheels, went down and caused a chain reaction that felled well over a dozen riders, holding up even more.

Unlike Contador, Aru narrowly avoided disaster before riding on to secure the pink jersey. The pair’s big rival from a tense opening week of racing, Tasmania’s Porte, came off his bike and eventually crossed the line 2:08 down on Modolo.

"It’s just how it is today – wet and nervous. It wasn’t really a surprise that there was a crash,” a resigned Porte told Eurosport en route to the Sky bus. "That's bike racing I suppose. Sometimes you're the hammer, sometimes you're the nail," he later added on Twitter.

Having started the race as one of the big favourites, Porte is now 5:05 down in 17th place. It remains to be seen if Porte will complete the race - or if he will withdraw in order to stay fresh ahead of Chris Froome's bid to win the Tour de France in July.

Sky’s best placed rider is Leopold Konig in 15th place, 4:24 down on Aru. But there was good news for Sir David Brailsford’s team with local boy Viviani moving back into the lead of the red jersey points competition – for which he is now odds-on favourite to secure given next week’s mountainous terrain.

Colombia’s Rigoberto Uran – the Etixx-QuickStep rider who won an individual time trial in last year’s Giro – finished safely in Aru’s group and is 2:02 down on the overall standingsm, time which he will hope to recoup in Saturday’s 60km race of truth.

Indeed, Uran's winning performance in last year's ITT saw the Colombian put 2:55 into Aru over a 42.2km course. It's such stats which suggest that this race is far from over...