After a weather-hit day's racing, Wout Van Aert took his first career Tour de France stage victory.
- Scroll down for full stage-by-stage guide & odds
- Click here for stage results & classifications
Wout Van Aert took his first career Tour de France stage victory as crosswinds ripped up the general classification.
Geraint Thomas and Ineos team-mate Egan Bernal profited hugely as French rival Thibaut Pinot was caught in a group who lost 100 seconds on the 217.5km stage from Saint-Flour to Albi.
Julian Alaphilippe was in the front group to retain the yellow jersey, but Thomas now vaults into second place overall, 72 seconds behind the Frenchman.
Crosswinds were always the threat on a stage listed as flat but which proved anything but straightforward.
Rigoberto Uran's EF Education First put the power down with 40km to go and successfully split the peloton, only to find themselves slipping into the second group on the road as Alaphilippe himself took up the baton.
Team Ineos were well positioned to keep Thomas and Bernal safely where they needed to be, along with Mitchelton-Scott's Adam Yates, UAE Team Emirates' Dan Martin, Movistar's Nairo Quintana and Jumbo-Visma's Steven Kruijswijk.
But there was full on panic for Pinot's Groupama-FDJ squad as they fell further and further behind.
After Van Aert edged out Elia Viviani to give Jumbo-Visma their fourth stage win of the Tour, the clock began counting to the groups left further down the road.
Pinot and Uran eventually crossed the line 100 seconds after the leaders, in a group which also included Trek-Segafredo's Richie Porte and Astana's Jakob Fuglsang, while Quintana's team-mate Mikel Landa was even further back to concede more than two minutes.
The new-look GC sees Thomas in second, 72 seconds behind Alaphilippe and four seconds ahead of Bernal in third.
Yates moves up to seventh, still one minute 47 seconds down, while Martin is in ninth, a further 22 seconds back.
But Pinot will curse his luck as he dropped from third place to 11th, now two minutes 33 seconds off yellow.
"EF had a little go and then Quick-Step," Thomas said. "We're just always attentive and ready. It was a really good day in the end.
"We had everyone bar two guys and we all just really committed. Bora (Hansgrohe) were there, there were plenty of guys turning. Behind, you can tell they went full-on on the climb to try to close it, but because they didn't get there they just ran out of gas and that's when the elastic snapped.
"On a day like today you'd never expect it really. It was just a positioning error from them and they've lost over a minute and a half so it's great from our point of view."
Tour de France: Stage-by-stage guide
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?