The Spanish veteran won the title in Innsbruck launching a long-range out-the-front sprint against Romain Bardet (France), Michael Woods (Canada), and Tom Dumoulin (Netherlands) 350 metres from the line.
But he arguably launched his attack on this victory much earlier, when the Innsbruck course was announced.
Much was made of Movistar's three-pronged approach at the Tour de France yet the 38-year-old didn't really want to race it. He told Spanish news site El Pais late last season if he could set his own race calendar for 2018, he'd skip the Tour and target the Giro and the Vuelta.
"Why? I have few opportunities left to win the world championships," he said. "I have six medals, but no gold. And in Innsbruck, it's very, very hard."
But he won today, his hunger for the rainbow jersey bringing him home as part of the last four men standing after a treacherously long 256km day in the saddle.
The emotion he unleashed after crossing the line in victory spoke volumes, sharing a lot of celebratory screaming and shouting with his Spanish teammates and staff.
“The truth is, this is incredible. I’ve fought for many years, and finally I get it," he said.
"The Spanish national team was attentive in every moment in the race. I controlled the distance from the finishing line. It was a very long sprint. I took my responsibilities and I launched my sprint at 350 metres, which was perfect for me.
"It’s the win of the national selection, of all the people who like me and support me. I’m speechless because I don’t believe it. I’ve been close many times. I’ve had several medals but I was still missing the gold. I’m caught by a huge emotion.”
'Highway to Holl'
All the pre-race buzz promised the Holl (literally hell) climb would be just that. With its ridiculously steep pitches including the maximum of 28 per cent, it delivered. The race arrived at the bottom with most of the climbing heads of state together, chasing Michael Valgren (Denmark) who'd slipped off the front after bridging to, then passing Peter Kennaugh (Great Britain) with 22 kilometres to race.
But the big names soon fell with just three Frenchmen - Bardet, Thibaut Pinot and Julian Alaphilippe - Valverde, Woods and Moscon passing Valgren to wrestle with Holl. Dumoulin laid in wait further behind, typically relying on his own tempo not panic.
Bardet's pace punished his teammate and race favourite Julian Alaphilippe who couldn't follow and Moscon too lost momentum on one of the steeper pitches leaving just Valverde, Bardet and Woods to approach the flatter section alone.
Dumoulin crested the top of the climb 10 seconds adrift but caught the leading trio with 1.3kms to go.
“On a flat finish, it was hard to beat a guy like Alejandro Valverde," Bardet said. "Earlier, I was hoping for Julian [Alaphilippe] or Thibaut [Pinot] to come back but once it came down to a sprint on the flat, I knew I’m not faster than this guy.
"Unfortunately, Julian wasn’t able to follow us in the last climb because he had cramps. I had a mechanical at the top and I was afraid to lose everything at that moment but everyone’s legs were burning and I didn’t lose ground.”
For Woods the race topped off a difficult season which turned out to be his best. After his wife earlier this year lost a son to stillbirth, the Canadian rebounded from the tragedy to win a monster stage at the Vuelta a España before the third place result in Austria.
“It’s certainly a slight surprise for me to make the podium but I was hoping for this," Woods said. "It was my goal coming into this race. When we did the course recon, I realized this last climb was for me. When drafting isn’t important, I’m pretty good.
"Up the Höll, my ears were ringing because the people were so loud and I could hear their cowbells. Even before the race, I told myself I’d try to get inspiration and energy from what the fans bring to the race. There were so many fans today.
"Coming from another sport [running], it’s been hard for me to believe that I could win when so good riders are in the field but my stage victory at La Vuelta helped me boost my confidence. Now I’m starting to believe in myself.”
How the race unfolded
Most of the race was characterised by an 11-rider break which established after an early five-rider lead group merged with six chasers out on the road. Robert Britton (Canada), Tobias Ludvigsson (Sweden), Kasper Asgreen (Denmark), Ryan Mullen (Ireland), Daniil Fominykh (Kazakhstan), Vegard Stake Laengen (Norway), Ryan Mullen (Ireland), Karel Hnik (Czech Republic), Jacques Janse Van Rensburg (South Africa), Ilia Koshevoy (Belarus), Laurent Didier (Luxembourg) held a steady advantage of around 18 minutes until the bunch started to get serious after the second lap of the circuit.
There were several flourishes behind in the bunch as it chased the leaders and as the race ramped up in the final 60 kilometres, but the Netherlands, France and Spain countered each other's moves and the attacks of others, through the sheer weight of their talented numbers.
The size of the lead group and its advantage slowly dwindled until just Asgreen and Laengen remained, the pair swept up with 22.8kms to go.
Australia's best on the day was Mitchelton-Scott's Jack Haig who finished 19th overall at one minute and 21 seconds behind Valverde. Rob Power was 70th of the 76 riders to finish the race.