Timo Kielich (Alpecin-Deceuninck) threw his bike across the line to win Antwerp Port Epic ahead of Rasmus Bøgh Wallin (Uno-X Mobility).
The 25-year-old Belgian took advantage of a solo attack with 30km to go and saved enough in his legs to withstand a challenge from the Dane, who bridged across in the final 7km.
Tim Merlier (Soudal-QuickStep) jumped around two other riders in the chasing group in the final 400 metres to grab third place.
Having a background in cyclocross and mountain biking, Kielich told Belgian broadcasters at the finish that played to his advantage on such a hectic day of racing:
"It's a bit of an advantage to the feeling on the gravel and the off-road sectors. Still, you have to push on the flat and on the straights."
The 182.2km race with 42 sectors of gravel and pavé saw a couple of early crashes, Sam Welsford (Red Bulll-Bora-Hansgrohe) first and then Arnaud De Lie (Lotto), taking both those contenders out of the race. De Lie tried to continue for a couple of kilometres, but stopped due to issues with his right arm and swapped his bike for an ambulance.
Then with just under 90km to go, most of the peloton made a left-hand turn which took them off the course as they seemed to follow one motorbike and only one course marshal visible on the broadcast alerting riders to a raised curt at that intersection. The race was neutralised for a short time to allow riders to reverse direction and return to the route.
A breakaway of four riders was down to three at that point - Filip Maciejuk (Red Bull-Bora-Hansgrohe), Tuur Dens (Flanders-Baloise) and Valentin Retailleau (TotalEnergies) - when the race was stopped and direction corrected. They were allowed to continue with a lead of close to two-and-a-half minutes, but one by one they succumbed to the fast pace behind and the race was back together with 40km to go.
Once that effort faded, the front of the peloton was down to about 30 riders, a constant replay of flat tyres, mechanicals and spills reducing the bunch.
Timo Kielich (Soudal-Deceuninck) attacked with 31km to ride, and for the next 25km he was alone at the front of the race.
The Dane was overtaken 6.9km from the finish by Uno-X Mobility's Bøgh Wallin. One kilometre later, the long line of the peloton drove with the two riders out front in their sights, still holding a 10-second gap.
Meanwhile, while a dozen riders went down and were slow to recover, however Gil Gelders (Soudal-QuickStep) was moved from the course to hospital where it was revealed after the stage by his team that he suffered a broken collarbone.
With 2km to go Lotto, Arkéa and Uno-X riders gathered at the front of the case with the peloton seeming to slow as sprint teams jockeyed for position and Arnaud Démare using one teammate to move out front. But the acceleration by Arkéa-B&B Hotels was not enough to catch the two escapees, who settled accounts by half a wheel, Kielich celebrating his first victory of the season.
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