James Wade became the first seeded player to fall at the Paddy Power World Darts Championship as he suffered a 3-2 defeat to Canada's Matt Campbell.
Four-time World Championship semi-finalist Wade twice led the match in sets at 1-0 and 2-1, but a resilient Campbell took the fourth set 3-0 to force a decider.
The final set began with an 86 checkout from Campbell before Wade missed three double attempts and the Canadian took full advantage to go 2-0 up.
Wade broke straight back with a 13-darter, but after he failed to take out 56 in the following leg, Campbell pinned double 18 at the first time of asking to wrap up the biggest win of his career.
CAMPBELL STUNS WADE! 🇨🇦
— PDC Darts (@OfficialPDC) December 19, 2023
What a moment for Matt Campbell, who produces one of the performances of his career to dump out four-time semi-finalist James Wade!
Wade becomes the first seed to crash out of this year's tournament! 😳
📺 https://t.co/f3RU9WTIoD#WCDarts | R1 pic.twitter.com/pzeieQuxUD
"For sure, this is the biggest win of my career so far, because of where it happened," said Campbell.
"I'd never won on the Ally Pally stage in four attempts before this year so this tournament has been huge for me.
"I think winning my first game against Lourence [Ilagan] helped me win this game because it got the monkey off my back.
"Now I'm looking forward to enjoying Christmas and seeing how far I can go in this tournament."
Michael van Gerwen began his bid for a fourth world title with victory over Keane Barry.
MVG was the headline act during the evening session, and he dropped just two legs in a dominant display over Barry, with the Irish youngster left to rue 14 missed doubles.
Van Gerwen averaged 98.17, pinning 60% of his checkout attempts, including a roof-raising 167 to progress to the third round.
"I'm happy to win my first game, and I'm happy with how I focussed today," said Van Gerwen.
"I'm pleased with my finishing but I could've done a lot more and I'm a little bit disappointed with my scoring.
"There's a lot of pressure on me and all the top players not to lose your first game; you don't want to let yourself down and you have to fight for every leg.
"I'm just happy to be coming back after Christmas and hopefully I can show what I can do."
Steve Beaton got his 33rd successive World Championship - and 22nd in the PDC - off to a winning start as he scored a 3-1 win over Dutch youngster Wessel Nijman.
The evergreen Beaton produced a strong display, raising the roof with a 123 checkout on his way to winning the opening set before winning the set two decider with a 14-darter to double his lead.
Debutant Nijman's response was immediate as he impressively reeled off three successive legs to win the third set and halve the deficit.
The second leg of set four saw both players leave a double after nine darts, and though Nijman won the leg to take a 2-0 lead, Beaton reeled of a trio of legs to book a second round meeting with Daryl Gurney.
BEATON BATTLES THROUGH! 👏
— PDC Darts (@OfficialPDC) December 19, 2023
Steve Beaton is back to winning ways on the Alexandra Palace stage!
The Bronzed Adonis overcomes some late nerves to close out an impressive 3-1 victory against Wessel Nijman!
📺 https://t.co/f3RU9WTIoD#WCDarts | R1 pic.twitter.com/1WVFX6EylP
"I think that was one of my best World Championship performances for a while," Beaton reflected.
"It was a really tough game, Wessel came out firing and I thought 'I'm in trouble here', but thankfully I found some good shots at the right times.
"I think playing a tough game first sets me up nicely for my next game.
"I still get the same buzz after all these years, playing in front of that crowd is unbelievable with the support I get."
Mike De Decker impressed in a 3-0 defeat of Dragutin Horvat as the Belgian progressed to the second round for a second consecutive year.
A strong display from De Decker saw him average 11 points more than his German counterpart as he breezed into round two where Madars Razma awaits.
German debutant Ricardo Pietreczko dropped just one leg in a 3-0 rout of Japan's Mikuru Suzuki, ending female hopes in this year's tournament.
Japan's Tomoya Goto enjoyed a dream Ally Pally debut as he dispatched of former World Championship quarter-finalist Ian White 3-1.
Goto, a winner of two PDC Asian Tour titles in 2023, took little time in settling onto the sport's biggest stage as he took the opening two sets.
White, who was also battling to keep his PDC Tour Card for 2024, rallied and took the third set, but was whitewashed by Goto in the fourth as the 27-year-old sealed his passage to round two where Ryan Searle awaits.
Jeffrey de Graaf picked up his first ever World Championship win, coming back from 2-0 down to defeat Ritchie Edhouse 3-2.
A keenly-contested encounter saw all of the first four sets go to last-leg deciders, as Edhouse missed a dart at tops to win 3-0.
De Graaf, representing Sweden for the first time in a World Championship, produced a magnificent fightback, winning another set decider in the fourth before finishing the stronger of the pair to seal his place in round two where he will take on Jose de Sousa.
Boris Krcmar reached the second round stage for a second successive year with a 3-1 win over Keegan Brown.
Despite losing the opening set, Krcmar was the stronger player throughout and the Croat will now take on Dirk van Duijvenbode in round two.
Tuesday December 19
Afternoon Session (12.30pm GMT)
First/Second Round (Best of 5 sets)
TV Coverage: Sky Sports Darts
Evening Session (7pm GMT)
First/Second Round (Best of 5 sets)
TV Coverage: Sky Sports Darts
Wednesday December 20
Afternoon Session (12.30pm GMT)
First/Second Round (Best of 5 sets)
TV Coverage: Sky Sports Darts
Evening Session (7pm GMT)
Second Round (Best of 5 sets)
TV Coverage: Sky Sports Darts