Raymond van Barneveld, Adrian Lewis, Gary Anderson and Jelle Klaasen reach PDC last four
Raymond van Barneveld came back from the brink to beat Michael Smith and reach the semi-finals of the PDC World Championship.
Van Barneveld, who won the last of his five world titles in 2007, lost the first three sets and was 2-0 down in the decider but won four legs in a row to set up a last-four clash with Adrian Lewis.
Smith won the opening set on a deciding leg after Van Barneveld had missed the bull on a 170 checkout.
The Dutchman only won one leg in the next two sets but stormed back to lead 4-3 as Smith's early confidence drained away.
But the 25-year-old from St Helens was not finished and won the eighth set against the throw before opening up what appeared a decisive 2-0 lead in the decider with a 130 checkout.
He had one dart at double top for the match in the next leg but missed it and did not get another chance as Van Barneveld showed all his experience to clinch an unlikely victory.
The 48-year-old, who beat title favourite Michael van Gerwen in the previous round, told Sky Sports: "He hit so many good finishes. When I was 3-0 down it felt like it wasn't going to happen.
"I blew it on my own throw and at 2-0 down (in the decider) I was thinking, 'here we go again'. I kept believing and made some really crucial doubles.
"I can't describe how happy I am. It could be my year. It's all about belief and about fighting back."
Lewis dropped his first sets of the tournament against Peter Wright but ran out a 5-2 winner. Wright had one dart at double top to pull it back to 4-3 but missed it.
Defending champion Gary Anderson is again in great form and was agonisingly close to a nine-dart finish in a 5-1 victory over James Wade.
The Scot threw eight perfect darts in the second leg of the second set but missed his attempt at double 12.
It was the only disappointment for Anderson in a dominant performance, and he said: "It's going all right so far and I'm happy.
"I've felt comfortable and confident ever since I got the first game out of the way. It was a good performance, although it would have been nice to have hit the nine-darter - but I'm sure that there will be one or two before the end of the tournament."
Alan Norris was also a double 12 away from a nine-dart finish in his clash with Jelle Klaasen but, unlike Anderson, did not have a victory to celebrate.
Norris led 4-3 but Klaasen won the final two sets as he followed up his victory over Phil Taylor by booking a semi-final clash with Anderson.