The new chapter, entitled Jai Hindley Giro d'Italia champion, has already revealed an unprecedented storyline and promises much more drama, heroism and victory spoils.

The old chapter was the sort which went on longer than expected, kept producing unexpected plot twists, featured passion, loyalty, heartbreak, chivalry, humour and eventual reward while retaining its unpredictable excitement to the final word.

That chapter was Richie Porte's Grand Tour career, and what a page-turner it was.

The storylines were intertwined. Hindley effectively became the first Australian to win the Giro in the final mountain stage where leader Richard Carapaz was denied the support of his best support rider due to Porte's enforced withdrawal the day before.

After 86 hours 31 minutes and 14 seconds in the saddle, the West Australian enjoyed a victory margin of just 78 seconds over the Ecuadorian Olympic champion as two gentlemen in Verona produced a dramatic finish of Shakespearean proportions.

Hindley became just the second Aussie - after Cadel Evans at the Tour de France in 2011 - to win a Grand Tour. Former pro Simon Gerrans said the achievement was equally important. Fellow SBS commentator Matt Keenan likened it to an Aussie tennis player winning the French Open or golfer claiming the US Open given that only one event could top it.

Verona's Roman amphitheatre echoed to Advance Australia Fair being sandwiched between U2's Where The Streets Have No Name and My Sharona by The Knack.

Hindley - who has taken 10 years to become an overnight sensation - deserved all the plaudits, but so did his compatriot who departed the event in far less celebratory circumstances a couple of days earlier.

Porte officially abandoned the race 100km into the 19^th of 21 stages, having begun the day in 24th place. There was some irony in his explanation - a frustrated cry of: "Gastro!" - being revealed by Bradley Wiggins given how the Eurosport correspondent had so often been the beneficiary of Porte's selfless work in the mountains, primarily in winning the 2012 Tour de France.

There was more irony in the choice of word both Porte and his team used to describe his decision.

"This is Richie's last Grand Tour, and we are gutted not to be taking him to Verona," INEOS Grenadiers tweeted.

Porte added on Instagram: "Gutted to have to leave @giroditalia so close to Verona but had a great few weeks before gastro got me. Yesterday was grim but the support has been overwhelming. Would have loved nothing more than to be with @ineosgrenadiers for one last mountain battle but it just wasn't to be."

Social media was awash with an assortment of disbelieving GIFs.

Few summed it up better than Porte's wife, Gemma, who turned - as trendy, young people tend to in moments of frustration - to face emojis, first loudly crying then weary, accompanied by the message: "That's all I have to say."

Porte has not completely finished his time as a pro. The 37-year-old will end his career at the Tour of Britain in September.

But he is done with Grand Tours.

This year's Giro d'Italia was his 17^th and just his fourth Did Not Finish.

His best results were third (2020) and fifth (2016) at Le Tour having set a high bar with seventh and the young rider classification in his maiden Giro a dozen years ago. He rode the world's biggest bike race for 11 consecutive years, helping Wiggins and Chris Froome become champions.

Four times he doubled up with two Grand Tours in a year.

Throughout that time, Porte never forgot where he was from, frequently describing his nationality as "Tasmanian" and finding time on visits home to support local initiatives like backing road safety campaigns and launching mildly-entertaining books about his home state's sport.

In a splendid interview with Peloton Magazine this week, he described the emotion of being cheered on in Italy by Gemma, their son Luca and daughter Eloise - whose birth he missed while securing a Tour de France podium finish two years ago.

"It justifies why this is my last season; to see the family is incredible for me," he said.

"But also now that my son is almost four years old, he can take it in a little bit and appreciate. So, it's nice he's going to have memories of what his dad used to do before he was a fat, beer-swilling couch potato."

While dominating shorter stage races like Paris-Nice, Tour Down Under, Tour de Suisse, Volta a Catalunya, Critérium du Dauphiné and Tour de Romandie, Porte developed a love-hate relationship with the Grand Tours.

High-profile crashes, untimely punctures, sickness and heart-wrenching misfortune beset his own prospects in those 17 races, which, even by my dodgy maths, equate to approximately 1400 hours of racing, which is about two solid months of buttock-numbing agony.

Porte's next challenge will be keeping in sight of his 62kg race weight as he transitions to that beer-swilling couch potato.

Next year will be the first since 2009 that he has not ridden a Grand Tour. This year's Tour de France, beginning on July 1, will be the first without a 172cm Tasmanian since 2010.

A legion of Australian supporters will miss that ... but also savour a return to sensible sleep patterns.