Hello and welcome to live coverage of stage 4 of the Giro d'Italia - and it's the first summit (or as good as when that summit is a volcano) finish of this year's race, an explosive ride up Mont Etna.

Today's winner, two years after he won on Abetone...

And here's the top ten from today's stage - with all the big guns present and correct. Don't worry, Nairo Quintana was there, just outside the top ten...

Here's the moment Slovenia's Jan Polanc (UAE Team Emirates) won the stage on Mount Etna.

Confirmation that Bob Jungels is the new pink jersey after the Luxembourg national champion finished in the same time as Thomas, who trails the new maglia rosa by six seconds after those four bonus seconds for third.

Geraint Thomas wins the sprint for third place to take the final bonus seconds - but will it be enough for the Welshman to take the pink jersey? We'll have to see where Bob Jungels was in the ensuing pack...

Ilnur Zakarin finishes second, 19 seconds down on Polanc. With six bonus seconds for him, he'll cut his losses a bit.

Jan Polanc is going to hold on - he grapples with the final steep ramp towards the line, and then coasts on the downhill run to the line. Up goes the jersey and he starts punching the air. Victory for Jan Polanc!

Remember that Zakarin is 20 seconds down on his GC rivals after losing time in stage 2 with a late puncture. It looks like he should cut those loses.

Now Zakarin rides clear of the regrouped pack - and no-one goes with him. Polanc is approaching the flamme rouge and he has 45 seconds to play with. He should do it.

Hansen is reeled in just as Dumoulin, Pinot and Zakarin open up a sprint, with Yates and Thomas just there - Mollema too.

Another attack by Igor Anton of Dimension Data - but it's covered by Jesper Hansen, who refinds his mojo. The Astana rider opens up a small gap - but it won't be enough.

Nibali is joined by his rivals and they manage to reel in Hansen. All of the big guns appear to be there - and Polanc now has 1:05 to play with but still 2km left to ride. He's swinging all over the road, but may hold on...

ATTACK: Vincenzo Nibali darts out of the peloton! Sparking a reponse by his rivals...

Under the 3-to-go banner for Jan Polanc and he now has 1:20 over the pack. Nail-biting stuff. Hansen is not making too much headway, mind, so if someone else but Polanc wins, it may not be him.

Attack by Jesper Hansen of Astana - the young Danish climber is highly rated, and he's zipped off in pursuit of Polanc and the stage win that will commemorate the late Michele Scarponi.

It looks like Polanc will hold off, so we'll have two races - for the stage win, and for the pink jersey. Bob Jungels, who has 10 seconds over the others on GC, is still there in this main pack, albeit a bit further back.

Interestingly, Quintana has dropped back and onto the wheel of Nibali. Thomas, who is nearer the front, now has Movistar's Amador on his wheel. It looks like a big attack is about to come. Pinot is also on Nibali's wheel, while Kruijswijk is just ahead. Polanc now has 1:50.

Under the 5-to-go banner for lone leader Jan Polanc, who rode clear of his remaining escapee, Jacques Janse van Rensburg at the beginning of this 17.9km climb. Back with the pack it's Franco Pellizotti who sets a steady tempo for his team-mate Vincenzo Nibali, with another Bahrain Merida rider, Kanstantsin Siutsou just behind. Then we have Van Garderen, Thomas and Quintana leading the throng of GC favourites.

Attack by Igor Anton of Dimension Data - but it comes to nothing. The Spaniard is swept up just before Pierre Rolland is caught by the Hermans-led peloton. So, just Polanc ahead now. He has 2:10 over those who can deny him a second stage win on the Giro.

Slovenian Polanc has won nothing since he took his only previous professional win in the Giro two years ago. He's struggling and grimacing, but he could well hold on. He's 2:18 ahead of Rolland, who is now under 20 seconds ahead of the peloton.