1 Amusingly 15-2
2 Foldom Blues 5-6fav
3 Man's Best Friend 12-1

1.09pm Qatar Prix Jean-Luc Lagardere

And they're off for this key race for juveniles … Crusherman leads for a long way but Amusingly, the ONLY filly in the race, wins well after a very slow start. That's impressive, especially given her slow start as she travelled really well up the home straight. And also a winner for trainer Francis Graffard, who saddles the hot favourite Daryz in the Arc later.

Social media reports suggest that Spirit Tango, who ran in the first race at ParisLongchamp today, has had to be put down. A very sad postscript to the Prix Marcel Boussac and news which follows the death of another horse on Arc weekend after the demise of another British runner in Fallen Angel on Saturday.

Green Empress provided trainer Joseph O'Brien with another big-race success in a stellar year when narrowly holding off Data to win the Prix Marcel Boussac, the forst race at ParisLongchamp on Arc day.

O'Brien said: "It's really special for us to have a Group One winner on this day and she has been progressive – she's only ever been beaten by Sun Goddess all year. She has a super pedigree, being by Saxon Warrior out of a Sea The Stars mare. We see her as a miler that might go 10 furlongs at some stage.

"We'll see how she comes out of today and discuss with the owners whether she'll go to America [for the Breeders' Cup] or whether we wait for next year."

O'Brien added: "We're very lucky to have the support of some great people and a wide variety of owners. For us it's about performing and executing at big meetings. It's fantastic to have a big winner on Arc day."

1.09pm Qatar Prix Jean-Luc Lagardere betting

1.09pm Qatar Prix Jean-Luc Lagardere preview

The second two-year-old race on the card is often assumed to be the colts' version of the Boussac, but it's over seven furlongs rather than a mile and while the great majority of the field are colts, fillies are also eligible and Francis-Henri Graffard's is an interesting contender with the 4lb sex allowance at the bottom of the card. Aidan O'Brien's Happily, in 2017, is the only filly to actually win this century, though, and as was the case in the opener, it is Joseph O'Brien, and not his father, who fields the likely favourite in Folsom Blues.

The son of Blue Point bolted up in the Group One National Stakes at the Curragh three weeks ago, finishing six lengths clear without being asked for maximum effort, and though a draw in stall 10 is not ideal, a repeat of that will make him hard to beat. That said, Folsom Blues has been beaten in three of his five starts to date, unlike the likely second-favourite, who arrives with a perfect 4-from-4 record. He is stepping up from Group Three company but clearly brings considerable talent to the fray, though I'll be more than happy to back Folsom Blues to beat him, not least because his latest rout was backed up by a strong time.

1 13-8f
2 8-1
3 11-2

12.31pm Qatar Prix Marcel Boussac

And they're off for the opener on Arc day … Nevermindtherain is slowly away and Green Empress the favourite is in midfield … Spirit Tango leads at halfway … So Lovely is right there as they turn for home … Green Empress now delivers her challenge and will just hold on a very strong challenge from Data. sadly, Spirit Tango appeared to suffer a very bad injury during the race.

12.31pm Qatar Prix Marcel Boussac betting

12.31pm Qatar Prix Marcel Boussac preview

A dozen runners for the Arc meeting's premier event for juvenile fillies, won last year by an Arc contender, Diamond Necklace. It's a race where the visitors have enjoyed plenty of success in recent years but the home team have also managed to hold their own, with 10 wins for French stables in the last 20 years and the remainder shared between Ireland and Britain. Aidan O'Brien, needless to say, is the most successful raider from across the water, with six wins since 2005, but it is his son, Joseph, who fields the likely favourite in the runner-up behind his dad's hugely impressive Sun Goddess in the Moyglare Stud Stakes last time.

She sets the standard, but she was also six-and-a-half lengths adrift and rivals like Christophe Ferland's who looks the pick of the locals, must be taken seriously. She is stepping straight into Group One company after winning a couple of minor events at Deauville and Chantilly but is still just 1lb behind Green Empress on Timeform's ratings with two fewer races in the book. Her stable-companion, is another to consider having run third in a Group Two last time. O'Brien snr fields three runners with (Ryan Moore) looking like the first-string but all three have something to find on ratings, while , beaten less than a length-and-a-half when fourth in the Rockfel at Newmarket nine days, is an interesting runner in Godolphin blue from the Roger Varian stable.

Here's the line up (and what a tasty one it is ) for today's action at Longhamp

12.31pm Qatar Prix Marcel Boussac SKY
1.09pm Qatar Prix Jean-Luc Lagardere SKY/ITV
1.47pm Prix de l'Abbaye de Longchamp Longines SKY/ITV
2.25pm Qatar Arabian World Cup SKY/ITV
3.05pm Qatar Prix de l'Arc de Triomphe SKY/ITV
3.50pm Prix de l'Opera Longines SKY
4.25pm Qatar Prix de la Foret SKY

We'll be giving you Greg's previews and the betting about half an hour before each race.

Bienvenue à Longchamp on one of the most eagerly anticipated days of the racing year: the Prix de l'Arc de Triomphe, the most valuable and prestigious race of the European season, is due off at 16.05 local time (1.05pm BST) and in all there are half a dozen Group One events on the card in the Bois de Boulogne on the busiest afternoon of top-level racing in Europe all year.

The Arc needs little introduction: it's roll of honour speaks for itself. Ribot, Sea-Bird, Mill Reef, Dancing Brave, Peintre Celebre and Sea The Stars all have their names up there in lights, and that's to name but six.

If you're going to click on one of those links, I'd recommend Sea-Bird for several reasons. You can't beat a Peter O'Sullevan commentary for one, and it's weird to see the field completely disappear from view for several seconds behind the trees in the middle of the track (the coverage cuts to a bemused Frenchman in the stands). But above all it's for the way he bursts clear at the top of the straight, putting the race to bed with an effortless, ground-eating stride that looks as though he's running on his own personal conveyor belt.

The Classics sort out the best horses of every generation, but the Arc sifts the all-time greats from the best of several generations could see join the very small band of colts that have won the Arc in successive years. Last year's winner has drawn well in stall five, but now gives weight to a strong cohort of three-year-olds including the Oaks winner; the Grand Prix de Paris winner; and his stable-companion, who took one of the key Arc trials, the Prix Niel, last month.

Among the older horses, the King George winner, has improved again this year at the age of five and bids to set the seal on Andrew Balding's best-ever season. And last year's narrow runner-up, will be a major player if she can bounce back to that form.

The going in Paris is unusually quick for the time of year, which is good news for some contenders – including Maltese Cross and Kalpana – and perhaps less so for Thundering On. But as the field turns for home and starts to fan out across the wide expanse of Longchamp's final straight, the question will be the same as ever: which horse will rise to the challenge and stamp its name in Arc history?

We're underway at Longchamp at 12.31pm BST with the Prix Marcel Boussac for juvenile fillies and there is more than an hour to build up to the big race after the Prix de l'Abbaye at 1.47, so kick back, relax and let the Guardian's live blog pilot you through one of the best afternoons of the racing year.