The rising British star launched the decisive move 40km from the finish, splitting the bunch to establish the group of favourites.
After another huge attack on the Hertstraat climb, Pidcock was joined by Van Aert (Jumbo-Visma) and Matteo Trentin (UAE Team Emirates) to form an elite trio at the head of the race.
Onto the final climb, and 21-year-old Pidcock held his own against Van Aert and Trentin, launching his sprint in pursuit of the Belgian and soaring past to take a huge victory.
The win is Pidcock’s first one the road since joining the WorldTour with Ineos Grenadiers at the start of the season.
How it happened
The 2021 Brabantse Pijl may have been missing some of the biggest stars, with both Mathieu van der Poel (Alpecin-Fenix) and reigning champion Julian Alaphilippe (Deceuninck – Quick-Step) both sitting out the race, but the start list was still stacked with talent.
Wout van Aert lined up in Belgium having taken some rest following an intensive start to the season, alongside the likes of Trentin and Pidcock.
Brabantse Pijl, raced over 201.7km from Leuven to Overijse, traditionally marks the transition on the cycling calendar from the cobbles of Flanders to the relentless climbs of the Ardennes Classic.
This year’s edition featured 24 notable climbs, with a majority of the ascending coming in the second half of the attritional race, as riders entered a 30km local lap at the finish.
After a constantly undulating opening 120km, riders took on the first of seven ascents of the Hertstraat cobbled climb (300 metres at 6.5 per cent average gradient), followed by the Moskesstraat, Holstheide and the Overijse climb to the finish line (1.5km at 3.6 per cent).
Riders crossed the finish for the first time after 136km of racing, then took on three full laps taking in all three climbs, before the final time up the Overijse climb to decide the winner.
The opening pace was established by a nine-rider breakaway that went clear after 40km of racing, with the likes of Bryan Coquard (B&B Hotels p/b KTM), Brent Van Moer (Lotto-Soudal) and Andreas Leknessund (Team DSM) all making the escape.
That group extended their advantage out to almost seven minutes in the middle section of the race, before the peloton began to gain on the break at the 100km mark.
Into the final 50km, a chasing group were able to bridge across to the breakaway, including Rémi Cavagna (Deceuninck – Quick-Step) and Robert Stannard (Team BikeExchange), with most of the favourites two minutes behind in the peloton.
The favourites sparked into action on the ascent of the Hertstraat with 40km to race as Pidcock launched his move, followed by Trentin and Van Aert, with the trio pulling a large group across to the existing breakaway with 35km to the line.
Into the final 30km and Trentin launched an opportunist solo attack, breaking clear of the leading group and extending his advantage considerably over the next 10km.
With 20km left to race, Trentin held 20 seconds over the elite chasing group, which still contained Van Aert, Pidcock, and Cavagna.
After looking to be struggling in the group, Pidcock then launched another huge effort on the final ascent of the Hertstraat, with Van Aert able to follow, as the cyclocross duo powered clear from their rivals.
The gap to Trentin dropped rapidly under the pressure being applied by Van Aert and Pidcock, and with 13km to go the three riders came together, holding 15 seconds over the chasing group behind.
Despite a huge effort from Benoît Cosnefroy (Ag2r-Citroën) on the Moskesstraat to close the gap to the leading trio with 10km to go, Pidcock, Van Aert and Trentin continued to hold off the chase.
Into the final 5km and the finish looked to be a nailed-on three-up sprint between the leading trio, as the gap to the chasers group to 30 seconds.
Onto the final climb to the finish with 1.4km to the line, Van Aert led the group, with Pidcock climbing out of the saddle in second wheel and nervously looking over his shoulder for the group behind, while Trentin looked composed at the back.
With 500m to the line the leading trio spread across the road, with Cosneyfroy then launching another huge attack from the chasing group and almost bridging across.
Van Aert launched his sprint first from the back of the group, 150m from the finish, but it proved too early as Pidcock jumped onto his wheel, powering past 25m from the finish to take victory.
Trentin wasn’t able to match the sprint of his rivals, sitting up and settling for third place.
Brabantse Pijl 2021, Leuven to Overijse (201.7km)
1. Tom Pidcock (GBr) Ineos Grenadiers
2. Wout van Aert (Bel) Jumbo-Visma
3. Matteo Trentin (Ita) UAE Team Emirates
4. Ide Schelling (Ned) Bora-Hansgrohe
5. Robert Stannard (Aus) Team BikeExchange
6. Dylan Teuns (Bel) Bahrain-Victorious
7. Benoît Cosnefroy (Fra) Ag2r-Citroën
8. Toms Skujinš (Lit) Trek-Segafredo
9. Oscar Riesebeek (ned) Alpecin-Fenix)
10. Andreas Leknessund (Nor) Team DSM