Despite trailing, William O'Connor is leading on the averages.

Per three darts, he is going at a rate of 87.48, with Slevin trailing at 83.86.

More importantly, Slevin leads.

Dylan Slevin has the darts for the first set and is left on 59 to take exactly that.

In two darts he pins it on double 20.

William O'Connor closes in on taking the set to a deciding leg, getting three darts at 52 to make it 2-2.

A single 20 sets up double 16, which he takes.

The two players share a first bump before the deciding leg.

A lower scoring third leg precedes William O'Connor scoring 140 to set up a 68 out.

The first two darts set up one at double 16, but there's too much on it.

Dylan Slevin takes out 86, which started with a one, on double 20 to lead the set.

Dylan Slevin gets down to 110 for a break of throw in the second leg, but does not find a treble until the final dart.

Chasing 100, William O'Connor misses doubles 20 and 10.

Slevin takes out double six to level up the match.

William O'Connor gets down to a finish first against the throw, with the crowd still singing "Zombie" back to him.

We've almost had a full leg of this!

He gets one dart at double 16 but misses. He will come back, though.

O'Connor splits the 16s on his return, but takes double eight for a first leg break.

William O'Connor walks out to "Zombie" by The Cranberries and the Alexandra Palace sing their hearts out.

O'Connor is facing his usual practice partner Dylan Slevin. The duo share a big hug before a couple of pre-match practice throws.

Slevin to throw first, game on!

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From all-Europe to all-Ireland, William O'Connor and qualifier Dylan Slevin meet next in a meeting between two players from the Republic of Ireland.

O'Connor is at his eighth consecutive PDC World Championship and twice, the 38-year-old has made the third round.

Slevin made his Alexandra Palace debut last year, losing 3-1 to Florian Hempel who has just beaten Jeffrey de Zwaan.

The winner of this first round match will face Belgium's Dimitri Van den Bergh, ranked 11th in the world, in the second round.

The match had four out of a possible five sets, but we did see 14 180s, with both Florian Hempel and Jeffrey de Zwaan taking seven each.

Brilliant match. A Friday night classic in Alexandra Palace!

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After a gruelling first match, this second has been superb and breathtaking.

Jeffrey de Zwaan needs a 93 checkout to stay in the tie but can only leave 36.

He comes back for it, but is still unsuccessful. Sums up his luck at times!

Hempel on double 10 pins it for the match and he is into the second round.

I think I need a sit down in a dark room after that one. Superb darts from both men!

That's more like it from both men!

Florian Hempl 180? Tick? Jeffrey de Zwaan 180? Tick.

Hempel is left with a Shanghai 120 for the leg on his throw.

The German takes the lot in a brilliant combination and he moves within one leg of the second round.

Florian Hempel has taken a real downward turn in the last few legs and if it was not for missed doubles on four and two from Jeffrey de Zwaan, Hempel would have been well out.

De Zwaan misses out on double nine and going to intentionally bust, he puts the third dart in treble one.

There is a reprieve as Dutch De Zwaan misses out a series of darts at double one. On double three, Hempel levels the set.

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Jeffrey de Zwaan is really getting going here!

He breaks Florian Hempel's throw on double 16 to lead set four.

Another leg starts with a 180 from Florian Hempel. These two have scored ridiculously.

On his throw, 140 leaves a 126 out to level the set, leaving himself double 20.

For the set, Jeffrey de Zwaan has the 170 big fish, but he goes treble-less.

On tops, Hempel misses either side of the bed, and on double 10, to level the set.

Never mind, De Zwaan picks out 111 to take the third set!

Jeffrey de Zwaan finds the 10th 180 of the match and his sixth to leave him a 67 out.

The last dart of his attempt goes just over double 20, but he will be back as Florian Hempel can't take out 164.

De Zwaan goes over once more before landing it to hold his throw.

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Another 180 from Florian Hempel continues this high-octane match.

The German gets three darts at 52, taking it out on two with a double 16.

What a start to the third set, a 180 from Jeffrey de Zwaan who has the throw.

Darts four and six also pick out treble 20s, and after nine darts he is left on 139, miles clear of Florian Hempel.

Treble 19 and bull are perfect, but De Zwaan cannons dart three just past double 16.

He comes back to take it in one for a 13-dart hold.

Both men are still playing excellently and if you looked at averages alone, you would think it is 1-1 in sets.

Florian Hempel's average after two sets is 98.8, with Jeffrey de Zwaan at 98.79.

Hempel has taken 50% of his double chances, while De Zwaan has only finished one out of five attempts.

Florian Hempel has the throw and the chance to win the second set without dropping a leg.

On 164, Hempel misses bull for a big finish, while another 180 from Jeffrey de Zwaan puts the pressure on.

Hempel takes out double 15 after two attempts for the second set.

A missed dart at double 20 from Jeffrey de Zwaan sees him miss a hold of throw.

It becomes an even tougher pill to swallow when Florian Hempel takes the same double on an 80 checkout.