PREMIER League semi-finalist Dave Chisnall edged out Jamie Caven 13-11 in a tie-break as the pair slugged out a 24-leg thriller in the BetVictor World Matchplay first round at Winter Gardens.

Although Caven held a slender 2-1 lead early on, following a break of throw in leg three, St Helens man Chisnall hit back to take a 6-4 advantage with the aid of a 13-darter and a 14-dart finish.

Caven took the next two to level at six-all, with the next six legs all going with the throw to send the game into a tie-break at 9-9, leaving a player needing to win by two clear legs.

The pair traded tops finishes and then shared the next two legs to remain locked at 11-all as Chisnall twice missed a single match dart, with double nine then seeing the number seven seed move 12-11 up and to the brink of victory.

With Caven throwing to force a sudden-death 25th leg, Chisnall kicked off with 140, 180 - his 13th of the game - and 135 to leave 46, and eventually sealed victory at the eighth attempt.

"It was a funny game but a good game before me because I won," said Chisnall. "Hats off to Jamie because he played well and kept plodding on and hitting his doubles and pulling it back, but thankfully I broke his throw in the last leg.

"I had a feeling that the game was going to go all the way because he's a great player. Sometimes I was in control but I was probably under pressure more than Jamie because I was almost always in the lead.

"My scoring's never a problem but sometimes it's my doubles which are a bit dodgy, but luckily I won tonight and that's all that matters."

Chisnall now faces World Youth Champion Keegan Brown, who enhanced his growing reputation as a contender at darts' highest level with another composed performance, as he followed up his giant-killings at the Grand Slam of Darts and World Championship by claiming another big-name victim.

Robert Thornton had gone into the event on a high following last weekend's European Tour triumph in Dusseldorf, but never recovered from seeing Brown take an early 5-1 lead as he suffered a sixth straight first round exit in Blackpool.

After Brown opened the game with a 14-darter, Thornton replied with a 12-darter only to see the Isle of Wight youngster win the next four to pull clear.

Thornton replied with finishes of 70, 40 and 62 as he reduced the gap to 5-4, but was crucially denied a chance to level as Brown fired in a 180 in a 14-darter to regain breathing space.

A 102 finish put him 7-4 up and he also took out another 14-darter to lead 8-5 before landing the bullseye to move to the brink of victory at 9-6.

Battling Thornton landed a 180 and finished 78 on tops to stay in the hunt, but Brown clinically sealed victory with another bull checkout, this time taking out 87 to seal his second round spot.

"I'm over the moon," said Brown. "I came here 12 years ago and watched Phil Taylor and Wayne Mardle in the final and thought it would be brilliant to play on that stage on day, and I've done that now.

"Robert's a player with Premier League experience so I wanted to get into him quickly and to take the first session 4-1 meant I could relax. Robert showed his class when he came back at me but thankfully I got there at the end.

"This is the hardest tournament to qualify for every year so I wanted to relax and play like I can do. To be in the last 16 makes me so happy."

The second round kicks off on Tuesday, with world number one Michael van Gerwen up against Welsh ace Jamie Lewis in their last 16 clash.

2013 World Matchplay finalist Adrian Lewis is up against another emerging Welsh star in Gerwyn Price, while Peter Wright takes on Andrew Gilding and Simon Whitlock faces Ian White.

BetVictor World Matchplay Monday July 20 First Round:

Robert Thornton 7-10 Keegan Brown

Dave Chisnall 13-11 Jamie Caven

Phil Taylor 10-2 John Henderson

Raymond van Barneveld 7-10 Andy Hamilton

Tuesday July 21 (7pm-11.30pm) Second Round

Peter Wright v Andrew Gilding

Simon Whitlock v Ian White

Michael van Gerwen v Jamie Lewis

Adrian Lewis v Gerwyn Price

Wednesday July 22 (7pm-11.30pm) Second Round

Dave Chisnall v Keegan Brown

James Wade v Brendan Dolan

Phil Taylor v Andy Hamilton

Gary Anderson v Mensur Suljovic

Second Round - Best of 25 legs * Each game must be won by two clear legs, with up to a maximum of five additional legs being played before the sixth "extra" leg is sudden-death. There will be no re-throw for the bull in this instance. For example, should a Second Round game (best of 25 legs) reach 15-15, then the 31st leg would be the final and deciding leg.