Julian Alaphilippe soloed his way into the yellow jersey as Geraint Thomas lost a handful of seconds to team-mate Egan Bernal on stage three of the Tour de France.
Scroll down for full stage-by-stage guide & odds
Alaphilippe took yellow off the shoulders of Mike Teunissen as he attacked on the final categorised climb of Monday's 215km stage from Binche to Epernay, while the steep finish in the capital of Champagne country was enough to see Thomas lose the wheel of Team Ineos colleague Bernal.
A five second gap between the two sees Thomas end the day seventh in the nascent general classification standings, 45 seconds down on yellow with Bernal in sixth, 40 seconds off Alaphilippe.
Victory for the 2018 King of the Mountains was little surprise on a Classics-style stage which seemed ideally suited to his explosive style.
"He may have designed today's stage himself," Mitchelton-Scott sporting director Matt White joked this morning.
"It's like the Amstel Gold Race in a French vineyard."
Even so, Alaphilippe had to execute in order to take his first career yellow jersey and he did so in style.
"I'm speechless," the 27-year-old said. "I don't realise what's happening to me. I knew this stage suited me.
"I managed to avoid any pitfalls and crashes. I felt good so I accelerated in the Mutigny climb but I didn't think I'd go alone. I gave everything.
"I heard I was 30 or 40 seconds ahead. It's difficult to meet the expectations being the favourite. I made it. I'm delighted."
Little happened on the long road south from Belgium, virtually flat until the final 45 kilometres when the riders hit the lumps of Champagne country.
The peloton was bearing down on Lotto-Soudal's Tim Wellens, the last survivor of the day's breakaway, as they hit the 12 per cent inclines of the Mutigny inside the last 20 kilometres.
As the summit came into view Alaphilippe launched his move, cresting the summit on Wellens' wheel before bursting clear, at the same moment as Jumbo-Visma's Teunissen was being jettisoned out the back.
Alaphilippe's advantage was already 50 seconds by the time he reached the foot of the descent.
There were still challenges to come - the uncategorised Cote du Mont Bernon inside the final five kilometres and then the eight per cent gradients of the finish itself - but Alaphilippe always looked in control as he powered clear.
He crossed the line some 26 seconds ahead of a much-reduced pack, led home by Team Sunweb's Michael Matthews, but the more notable gaps appeared behind as Thomas lost the wheel of Bernal in the finale.
The Welshman will be grateful that Groupama-FDJ's Thibaut Pinot was the only other general classification hopeful in front of him, and though five seconds is a tiny margin, it could prove a significant moment as the co-leaders vie for supremacy within Team Ineos.
Tour de France: Stage-by-stage guide
July 9, Stage 4: Reims to Nancy (213.5km)
Funny things can happen in the first week of the Tour. Broadcasters could be counting on it, because stage four might otherwise be in danger of turning into a snooze fest. Just shy of 200 kilometres of near pan-flat roads precede one late lump on the horizon before a straightforward run to a sprint finish in Nantes.
July 10, Stage 5: Saint-Die-des-Vosges to Colmar (175.5km)
The first proper hills of the Tour come as they ride into the Vosges, where stage five takes the peloton over four categorised climbs, with two rated as category two. With general classification hopefuls perhaps keeping their powder dry for the next day, this could be one where a breakaway prospers.
July 11, Stage 6: Mulhouse to La Planche des Belles Filles (160.5km)
Here we go then. The GC battle should come alive over seven categorised climbs, four of them category one, including the summit finish at La Planche des Belles Filles. Recent Tour history suggests whoever wears yellow here will wear it in Paris - see Bradley Wiggins in 2012, Vincenzo Nibali in 2014 and Chris Froome in 2017 - but the Champs-Elysees is long, long way away. This year sees a change at the summit, with an extra kilometre including 24 per cent gradients and gravel sections.
July 12, Stage 7: Belfort to Chalon-sur-Saone (230km)
After those exertions there is a recovery day of sorts with flat roads taking the race south west towards wine country. However, at 230km this is hardly a rest. Expect a long, slow day with every chance of a headwind harassing the peloton. Chalon-sur-Saone is where Britain's Brian Robinson won the second of his two Tour stages in 1959 - and by a margin of some 20 minutes. That will not happen this time though, with a sprint finish expected.
July 13, Stage 8: Macon to St Etienne (200km)
The Massif Central does not boast the beasts of the Alps or Pyrenees, but with seven categorised climbs the Tour's route designer Thierry Gouvenou has made sure this will be a draining day on the legs. A day with multiple possible attack points is designed to break the control of the big teams - read Team Ineos.
July 14, Stage 9: St Etienne to Briourde (170.5km)
A stage that finishes in Romain Bardet's home town is not really difficult enough for the great French hope to take victory, but how the locals would love to see the 28-year-old end Bastille Day in yellow with his family watching on. As for the stage, expect a big breakaway, full of Frenchmen, attack each other on the final climb which peaks 13 kilometres from the line.
July 15, Stage 10: Saint-Flour to Albi (217.5km)
The peloton must wait until Tuesday for their first rest day but as they climb on their bikes one more time, riders will be grateful most of the second half of this stage is essentially downhill. The sprint teams will hope for a straightforward day.
July 17, Stage 11: Albi to Toulouse (167km)
The last time a Tour stage finished in Toulouse, back in 2008, a young debutant by the name of Mark Cavendish took victory. After two tough years of illness, injury and misfortune the Manxman could certainly use a repeat 11 years on. With the mountains looming, it will be the sprinters' last chance for a while.
July 18, Stage 12: Toulouse to Bagneres-de-Bigorre (209.5km)
And so to the Pyrenees, though stage 12 is just a warm-up. Two category one climbs, the Peyresourde and the Hourquette d'Ancizan, provide the focus before a long descent into Bagneres-de-Bigorre where Ireland's Dan Martin took his first stage win in 2013.
July 19, Stage 13: Pau to Pau (27.2 time trial)
The only individual time trial of this year's Tour will be a test of strength over a rolling course, but also a test of the head. Go too deep and riders will surely be burned on the mountain tests to come over the weekend. The eventual winner of the Tour has finished in the top four of every long time trial since 2011 but this time they may prefer to save their legs.
July 20, Stage 14: Tarbes to Tourmalet Bareges (117.5km)
The first of the five HC climbs comes on stage 14 - a short, sharp 117.5km race to the summit of the storied Tourmalet. The highest surfaced climb in the Pyrenees has featured in the Tour 87 times but this will be only the second stage finish at the summit.
July 21, Stage 15: Limoux to Foix Prat d'Albis (185.5km)
The second summit finish in a row comes on a more traditional Pyrenean stage, which rolls over several testing climbs, sapping the legs and the minds. However, there is no tradition to the finish with the Prat d'Albis making its Tour debut.
July 23, Stage 16: Nimes to Nimes (177km)
After the second rest day comes a pretty flat stage, though with constant changes of direction on a loop starting and finishing in Nimes, the sprinters' plans could be disrupted if the Mistral wind blows.
July 24, Stage 17: Pont du Gard to Gap (200km)
And so towards the Alps, though stage 17 features none of the big passes on a day of gradual climbing up to Gap. This is the stage in the race where breaks are often allowed to stay clear as the battle for yellow rages behind, but this day has been made to be utterly unpredictable. A punchy final climb of the Col de la Sentinelle could be a springboard, while it's not inconceivable some of the sprinters survive in the main group.
July 25, Stage 18: Embrue to Valloire (208km)
There may only be five HC climbs in the entire Tour, but two of them come in a single day as the riders tackle the Izoard and the Galibier before dropping down to the finish in Valloire. The stage winner should come from whichever group first crests the Galibier - appearing for the 60th time as the Tour's most regular Alpine venue - and this could be a decisive day overall.
July 26, Stage 19: Saint-Jean-de-Maurienne to Tignes (126.5km)
Stage 19 is a leg-sapping day designed to test the resolve of anyone planning a late move in the general classification. The Iseran - at 2,770m the high point of the Tour - comes in the middle of the stage and casts a long shadow before the shorter climb to Tignes offers an opportunity for attacks.
July 27, Stage 20: Albertville to Val Thorens (130km)
The last chance saloon for GC hopefuls does not look an inviting one. The final climb of the Tour is the 33.4km HC slog up to Val Thorens. If ever there was a Tour designed for a true climber, one with only a handful of time trial kilometres and four HC climbs in the last three days could be it.
July 28, Stage 21: Rambouillet to Paris Champs-Elysees (128km)
There are two big questions on the final day. Will the yellow jersey winner choose a few glasses of champagne or, as Geraint Thomas did last year, prefer a beer or two as they celebrate along the roads of the Parisian suburbs? And which sprinters will have survived the mountains in order to battle it out on the Champs-Elysees?