REIGNING champion Michael van Gerwen started the defence of his William Hill World Darts Championship title with a hard-fought 3-1 victory over Joe Cullen at Alexandra Palace, where qualifier Cristo Reyes caused a huge upset by dumping out 13th seed Wes Newton in a sudden-death leg and Keegan Brown ousted John Part.

All five sets in van Gerwen's first match back at Alexandra Palace since he claimed the Sid Waddell Trophy in January went the full distance, and they could have gone either way with Cullen twice missing set darts, but in the end the Dutchman raised his game at the right time.

Van Gerwen opened the game by scoring 140, 180 and 149 to leave himself on 32 for a ten-darter, but Cullen showed he would not be rattled by taking out 161 to stun the World Champion with a 12-dart leg.

Van Gerwen recovered to take the set despite struggling, and it was a similar story in the second as Cullen missed two darts for the set to level the game, enabling his rival to go 2-0 up.

Van Gerwen took out 104 in the third set after Cullen had moved two legs up, and although he missed further set darts the Yorkshireman recovered to take out 114 to finally get a deserved set on the board.

His visible celebration only served to give the Dutchman a jolt though, as he hit seven perfect darts when going ahead in the fourth set. Cullen stormed back with finishes of 128 and 104 to force another decider, but van Gerwen nailed 84 to seal the win.

"Joe made me play well - both of us also found it difficult with the pressure but a win is a win," said van Gerwen. "He played really well "In the first leg I was left on a double and he took that shot out and I thought today is not going to be my day - Joe's a fantastic player I know that. I just want to do well and with all the pressure I'm happy to just get the win.

"Of course there's more pressure as champion but I got through it and I've got a week off now so I'll be happy to go home and then come back stronger for the rest of the tournament.

"I need to play more consistently, I made too many mistakes and sooner or later someone's going to make you pay for that.

"I'm going home for Christmas, I'm flying back tomorrow and them coming back on Boxing Day so I'll be enjoying my Christmas and then coming back stronger."

Spanish qualifier Cristo Reyes won his preliminary match against Christian Perez with ease as he claimed a 4-0 whitewash victor, and that match on the big stage obviously gave him huge confidence as he returned for the last match of the night to win a sudden-death thriller against Wes Newton.

Tenerife's Reyes, 27, quickly moved two sets up up on the three-time quarter-finalist, with a 126 finish helping matters, but Newton hit back with a 130 checkout on the bull as he hit back in the third set.

Newton then won three straight legs in the next to level the game as the dream upset victory for Reyes seemed over, but to his huge credit he went toe-to-toe in the deciding set, which kicked off with a 121 finish from Newton.

The two traded legs to force the match into a tie-break, but even then they couldn't be separated as the game went to five legs all to force a sudden death final leg.

Following confusion on stage as to whether or not the players should throw for the bull again in the deciding leg, Reyes capitalised and hit double 16 at his first attempt to grab by far the biggest win of his career and a second round place at the World Championship.

"Playing in the preliminary round helped a lot with the nerves, I was far less nervous coming back than I was in the preliminary round," said Reyes.

"I'll be going back to Tenerife now for Christmas and then we'll come back - I didn't have a flight booked back obviously but we'll sort that out. This is great for me and for Spanish darts."

Another upset saw debutant Keegan Brown survive a strong comeback to knock out three-time World Champion John Part 3-2 in their first round tie.

Reigning World Youth Champion Brown stormed into a 2-0 lead by winning the opening six legs of the match, hitting two 180s as he bullied Part on scoring and gave him few opportunities on doubles.

A seventh leg on the spin to start the third set looked to spell the end for Part, but the Canadian came roaring back and produced three superb finishes of 109, 84 and 115 to level the game at two sets all, leaving Brown visibly stunned.

A deciding set promised drama, but it proved to be a step too far for Part as Brown raised his game again and took all three legs, despite a wobble on closing out the match on tops, to book his place in the second round - where he could face another World Champion in Adrian Lewis.

"John showed he's a true World Champion by coming back from 2-0 down, not many players would be able to come back from 2-0 down but he showed his class there," said Brown, who will return to his day job as a medical lab assistant on the Isle of Wight before his second round match.

"There's no real time to enjoy it, I'll be back at work on Monday morning and I'm working Christmas Day and Boxing Day as well!"

Jelle Klaasen overcame fellow Dutchman Christian Kist 3-1 in their battle of former Lakeside Champions to book his place in the second round.

There was not much between the two in the first two sets, which both went the distance, but Klaasen held his nerve edge them both.

Kist hit back with a 3-0 set, but Klaasen was a cut above in the next as he also took it without reply with a 109 checkout the highlight as he claimed his place in round two.

The first round continues on Friday, with Phil Taylor beginning his bid to win a 17th World Championship title as he takes on Germany's Jyhan Artut.

Peter Wright, last year's beaten finalist, takes on Welsh debutant Gerwyn Price, while 2012 runner-up Andy Hamilton meets Canadian newcomer Dave Richardson and Stuart Kellett plays either Finland's Kim Viljanen or Germany's Sascha Stein, who meet in the preliminary round.

WILLIAM HILL WORLD DARTS CHAMPIONSHIP.

Preliminary & First Rounds.

Thursday December 18.

John Part (30) 2-3 Keegan Brown.

Christian Perez 0-4 Cristo Reyes (P).

Jelle Klaasen (29) 3-1 Christian Kist.

Michael van Gerwen (1) 3-1 Joe Cullen.

Wes Newton (13) 2-3 Cristo Reyes.

Friday December 19 (7pm).

Andy Hamilton (12) v Dave Richardson.

Kim Viljanen v Sascha Stein (P).

Peter Wright (5) v Gerwyn Price .

Phil Taylor (2) v Jyhan Artut.

Stuart Kellett (32) v Kim Viljanen/Sascha Stein.