The 29-year-old built on a superb spring, which included finishing second at the Tour of Flanders, by attacking multiple times throughout the day, his final one on the Camphin-en-Pévèle cobbled sector proving decisive.
In what has gone down as the fastest ever edition of the Hell of the North with an average speed of 45.792kmh, Van Baarle was a deserving winner, the Dutchman managing to help form an early crosswind-induced split after just 40km of racing, and later single-handedly catching up to the day's previous leaders despite being one of many to suffer a puncture in a day that will also be remembered by the huge amount of flat tyres.
He won the race by a massive 1-47, and continues his team's outstanding April, having won De Brabantse Pijl with Magnus Sheffield just four days earlier and Amstel Gold with Michał Kwiatkowski a week ago. The British team also won two stages and the overall at the Tour of the Basque Country.
Behind, Wout van Aert (Jumbo-Visma) defied his own expectations to place second ahead of Stefan Küng (Groupama-FDJ) in a four-man sprint to round out the podium, with Tom Devriendt (Intermaché-Wanty-Gobert Matériaux) and Matej Mohorič (Bahrain-Victorious) - the pair who had spent so long out front together during the day - having to settle for fourth and fifth, respectively.
Pre-race favourite Mathieu van der Poel never looked at his best, and the Alpecin-Fenix man eventually finished in ninth.
How the race unfolded
The most-anticipated one-day race of the season started under blue, sunny skies in Compiègne, the peloton 257km from the famous velodrome and backed by a favourable tailwind.
While normally a breakaway would form and not splinter until there were double-figure kilometres remaining, the action this year kicked off almost straightaway, several small groups forming for a brief stint at the head of the race before drama erupted with 210km to go.
A crosswind caused echelons - an event so rare in the Queen of the Classics - that split the peloton in two, key favourites like Van der Poel, Van Aert and Mads Pederson (Trek-Segafredo) missing out, while Ineos Grenadiers packed in seven riders and Quick Step - Alpha Vinyl counted six in a 73-man group.
The gap to the Van der Poel group fluctuated between 90 seconds and two minutes for around 100km, only 2014 winner Niki Terpstra (TotalEnergies) briefly enjoying a noteworthy lead out front for around 10km during that period.
While the gap remained fairly stable and with Alpecin-Fenix forced to commandeer the pulling of the peloton, multiple riders suffered punctures on the dusty cobbles, with five riders caught stranded in just 200m in one of the first cobbled sectors.
One hundred and twenty kilometres from the finish, Jens Reynders of Sport Vlaanderen - Baloise create a solo gap of around 45 seconds and he was looking good until a front wheel puncture derailed him. The Belgian was forced to accept a replacement wheel from the Shimano motorbike but incomprehensibly the wheel was changed in the middle of a cobbled sector, with the chasing group thankfully only narrowly avoiding what would have been a very avoidable crash.
A few kilometres later, Mohorič came to the party and immediately built a gap to the main group of around 35 seconds, the Slovenian joined by Casper Pedersen of Team DSM, Devriendt, Laurent Pichon (Arkéa Samsic) and Quick-Step Alpha Vinyl's Davide Ballerini.
The five riders had a lead of around a minute to chasers Connor Swift (Arkéa Samsic) and Nils Politt (Bora-Hansgrohe) as they entered the Forest of Arenberg, with their advantage to the group containing Van der Poel swinging back out towards the two minute mark.
As the toughest cobbled sectors appeared every few minutes, there was no substantial response for around 30km, with Mohorič, Devriednt and Pichon looking good value for potentially holding their gap to the end.
At 65km to go, Matteo Trentin (UAE Team Emirates) and Van Aert both tried unsuccessful attacks, but eight kilometres later the main peloton then split into an elite group of 11, with Van Aert, Van der Poel, Van Baarle, Ben Turner (Ineos Grenadiers), Jasper Stuyven (Trek-Segafredo) and Yves Lampaert (Quick Step - Alpha Vinyl) all present.
The gap to the Mohorič group dropped to just over a minute with 50km separating them from Roubaix, and it was on the sector 12 cobbles of Auchy-lez-Orchies that Van Baarle set off in a lone pursuit, the Dutchman creating an advantage of around 15 seconds to his previous road companions.
As Van Baarle rode equidistance between the leaders and the chasers, Van Aert was very active behind, Küng and Van der Poel having to close down the Belgian's attacks.
On a day characterised by the sheer number of punctures - something that will surely result in debate around the use of tubeless tyres - both Mohorič and Van Aert suffered untimely punctures around the 40km to go mark, resulting in the former having to forfeit his lead and leave the little-known but valiant Devriednt out front alone to manage a 25 second lead.
Van Aert, who had questioned his ability to be able to race for the win due to a recent Covid-19 infection, attacked almost as soon as he caught back up to the group he was shedded from due to his flat tyre, but once again he was unable to shake others.
At 29km to go, a major attack followed, Lampaert jumping clear with Mohorič, the duo catching Devriednt and then the trio becoming four when Van Baarle bridged the gap, too. The quartet had a lead of around 30 seconds.
Behind, Van Aert remained desperate to still be in the hunt for the victory, attacking with Küng at 22km from the finish line, the pair catching Stuyven who had only just gone himself. Most significantly, though, Van der Poel was dropped, the Dutch superstar unable to respond to the attack.
As they approached the four star Camphin-en-Pévéle sector that also signalled 19km from the line, Stuyven the solo chaser in between groups punctured, while up ahead Van Baarle made what would prove to be the winning attack.
The trio of Mohorič, Lampaerts and Devriednt let Van Baarle go initially before the former two responded. But Van Baarle was gone - his lead steadily increasing and by 10km to go, and just two cobbled sectors to tackle, the chase had given up, paving the way for Van Baarle to become the first Dutch winner in eight years.
There was still some drama left to be written - Lampaerts spectacularly being upended by a stray arm of a spectator that resulted in him crashing hard on the cobbles - but Van Baarle didn't less his chance pass up, with Van Aert sprinting for second ahead of Küng who took third.
Result: Paris-Roubaix men's 2021: Compiègne - Roubaix, 257km
1. Dylan van Baarle (Ineos Grenadiers) in 5-37.00
2. Wout van Aert (Jumbo-Visma) at 1-47
3. Stefan Küng (Sui) Groupama-FDJ
4. Tom Devriendt (Bel) Intermaché-Wanty-Gobert Matériaux
5. Matej Mohorič (Slo) Bahrain-Victorious, all at same time
6. Adrien Petit (Fra) Intermaché-Wanty-Gobert Matériaux, at 2-27
7. Jasper Stuyven (Bel) Trek-Segafredo
8. Laurent Pichon (Fra) Arkéa Samsic, all at same time
9. Mathieu van der Poel (Ned) Alpecin-Fenix
10. Yves Lampaert (Bel) Quick-Step Alpha Vinyl
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