Hello and welcome to live coverage of what could be the key stage of this year's Giro d'Italia - it's stage 19, a mammoth 184km ride from Venaria Reale to Bardonecchia that includes the Cima Coppi - the Colle delle Finestre - a second 2,000+ metre climb to Sestriere and the final steep ascent of the Jafferau. If yesterday was tough, then this takes things to a whole new level...

Ben Hermans (Israel Cycling Academy) and Davide Formolo (Bora-Hansgrohe) both have a pop before the race crests the San Giovanni peak half way up this climb. But they're given no leeway. No surprise there - Formolo may not be a GC threat in terms of the pink jersey, but he's only 10 minutes down in 17th place and there are too many riders ahead of him wanting to protect their positions in the top 10 or 15.

A reminder that Simon Yates not only leads the overall standings but he's also the current king of the mountain on 91pts to his nearest rival Giulio Ciccone's 52pts. So, because the Briton is in pink it's the Italian youngster from Bardiani-CSF who is in blue, five points clear of another Mitchelton-Scott winner, Esteban Chaves, who has done next to nothing since winning on Mount Etna and dropping without a trace.

The riders are onto the Col San Giovanni, which precedes the Colle del Lys, the first categorised climb of the day. Essentially they're one climb, but the latter starts as the former finishes. The San Giovanni is far steeper and tougher, with a maximum gradient of 12% and an average of 7.1%. The whole ensemble is a Cat.2 offering of 13.8km at an average of around 5%.

Giovanni Visconti (Bahrain Merida) is the latest rider to open up a small gap, the Italian darting clear with a couple of others. But again, there's no let up from the peloton and it comes to nothing.

Now Movistar and UAE Team Emirates pick it up in a bid to force something to stick. The Spanish team want to forge an opening for their man Richard Carapaz, who is trailing Miguel Angel Lopez by 1'05" in the white jersey classification. Meanwhile, UAE have Fabio Aru in mind - he knows this climb well and took a day off yesterday having already plummeted down the standings last weekend.

ATTACK! And no prizes for guessing who... it's Marco Frapporti of Androni Giocattoli. He's been a livewire throughout the race, but took a day off yesterday to allow his pals Davide Ballerini and Mattia Cattaneo have a pop. But he's chased down by a cluster of riders and it comes back together once again.

I have no idea what any of this means, but for the techies out there, this may be of interest...

Still no break has formed as the road steadily rises towards the foot of the first of our four categorised climbs today. No surprise there - the composition of any break today could prove vital. The likes of Yates, Froome, Dumoulin and Pozzovivo will be keen to get men in there, and then there are the teams after a stage win such as Astana and UAE Team Emirates (for whom Fabio Aru will be chomping at the bit).

Big day for Tom Dumoulin. He finally found a chink in Simon Yates' pink armour yesterday. Can he exploit that today and set up a grand stand finale tomorrow?

158 riders took to the start - that's just 18 fewer than the peloton which started the race in Israel. In fact, make that 17 because Kanstantin Siutsou actually withdrew before the race started after crashing heavily in training. Chris Froome and Miguel Angel Lopez also crashed that day - and are finally showing signs of better form. Having won on the Zoncolan, could Froome revive his faint hopes of taking the maglia rosa today?

Here was the scene as the riders rolled out of Venaria Reale this morning. They have negotiated the neutral zone and the stage is now under way!

Here's what's in store for the riders today - with that brutal gravel track ride up to the highest point of the race, the splendid snow-capped Colle delle Finestre, the clear highlight.

Yesterday, Britain’s Simon Yates saw his lead over Dutchman Tom Dumoulin halved to 28 seconds after being distanced near the top of the final climb to Prato Nevoso in Stage 18, won by the German youngster Max Schachmann from the break. For the first time in the 101st edition of the Giro d’Italia, Mitchelton-Scott’s Yates lost time in a summit finish following a devastating attack by defending champion Dumoulin in the final two kilometres of the 198km stage from Abbiategrasso. Read more below...