It came down to a final dash to the line from three very tired men who had all come to the front group from separate attacks from the disintegrating peloton and it was Pedersen who proved to still have the legs to sprint to the win.
The Danish 23-year-old overcame the sprint of the highly-credentialled Trentin in the final few hundred metres to take victory on a day that will be remembered for the atrocious conditions and incredible feats of fortitude from the riders competing at the front of the race.
"I just hoped that when I saw the finish line all the pain would be gone and I could do a good sprint," said Pedersen after the race. "It's six and a half hours on the bike, and everyone is on the limit. Anything could happen in that sprint.
"You have to be focused the whole day and stay in front - but it's one of the last races of the season so it's just about being focused for six and a half hours, not have any bad luck and hope for the best."
Pedersen has shown a lot of promise in his young career, notably finishing second at the 2018 Tour of Flanders, but was without a win in 2019 until the week prior to the world championships, taking a solo win at GP d'Isbergues.
“A lot changes for anyone who wins the World Championships, so it’s going to change a lot for me," said Pedersen.
“I’m finished with playing the underdog. I think that’s going to be pretty much impossible from now on. That’s a new situation and I have to race in another way from now on.”
How the race unfolded
Miserable conditions and hard racing was the narrative of the elite men's road race for 2019, with highly credentialled riders simply happy to finish the race as the elements assaulted the peloton in the harsh northern climes of Yorkshire.
The scale of the deluge was evident before the race, with flooding forcing the UCI to shorten the race route by 23.5km to 260 kilometres in total length and delay the start.
The riders nonetheless found the going exceptionally tough, with pre-race contenders pulling out in droves as crashes and the attritional nature of the race took their toll.
An early break containing the Grand Tour winning trio of Nairo Quintana (Colombia), Primoz Roglic (Slovenia) and Ricard Carapaz (Ecuador) got to a maximum advantage of four minutes but proved to still be the traditional sacrificial lambs of the race, despite the pedigree of the riders present.
Australia's Rohan Dennis, fresh off defending his world championships title in the individual time trial, spent the early parts of the race in a similar effort, carrying on solo at the front of the peloton to keep the race in check for team leader Michael Matthews.
The breakaway surrendered as the riders reached the first of nine finishing circuits and the race faced its first major upheaval as Philippe Gilbert (Belgium) crashed, with time trial silver medallist Remco Evenepoel stopping to help the pre-race contender. Try as they might, the pair were never able to rejoin as they found themselves riding against their own teammates, with Tim Declercq prominent at the front of the peloton, driving the pace for Greg van Avermaet.
The peloton continued to grind a solid tempo through the laps of the finishing circuit, with the abandonments of defending champion Alejandro Valverde (Spain), Dan Martin (Ireland) and Alexey Lutsenko (Kazakhstan) showing that it was far from an easy ride in the main group.
A testing attack from Lawson Craddock (USA) and Stefan Kung (Switzerland) with just over 60 kilometres remaining saw the pair work well together and take a small advantage, but the combined efforts of the French and Belgian squads ensured that the pair never got too much of a gap.
The crash of veteran Michael Albasini (Switzerland) with 47 kilometres left to race split up the peloton a little bit and in the ensuing reforming Pedersen took the opportunity to bridge over to the front pair, powering over the gap and dropping Craddock immediately as Kung clung to his wheel.
Mike Teunissen (Netherlands) eventually bridged over as well, and Gianni Moscon (Italy) joined later still to make it a leading group of four with a slim lead of 20 seconds over the chasing bunch with three laps of the 14 kilometre circuit remaining.
Teunissen was dropped from the front group, forcing a rethink from the Netherlands team. With 33 kilometres left, pre-race favourite Mathieu van der Poel (Netherlands) made his move, jumping clear with Trentin in tow.
The pair quickly bridged the gap and worked with the front group to push the advantage over the peloton stretching their lead over the much-diminished main group to 50 seconds with 20 kilometres left to race.
A brief moment of weakness from Moscon saw the Italian dropped, before fighting his way back to restore the numerical that Italy had in the front group.
The next man to blow up in spectacular fashion was van der Poel, who had looked incredibly strong in taking long, hard turns to push out the lead of the attack, but suddenly cracked with 13 kilometres remaining and began moving at a snail's pace.
An attack from Kung beyond the pain barrier on the final major ascent of the race was too much for Moscon, but allowed teammate Trentin to sit on and wait for the return of his compatriot.
Coming into the final sprint Pedersen led for the final kilometre at a soft temp before Trentin took up the sprint with 200 metres remaining. While he initially took the lead, a quick response from the Dane took him past the renowned fast man and the result was never in doubt from there.
Pedersen punched the air in joy before collapsing after the line, with a bitterly disappointed Trentin and an utterly spent Kung completing the podium.