An enthralling day of action at Alexandra Palace saw Raymond van Barneveld, Adrian Lewis, reigning champion Gary Anderson and Jelle Klaasen book their places in the semi-finals of the PDC World Darts Championship.
Van Barneveld was forced to call on all his experience as he followed up his victory over world number one Michael van Gerwen with a come-from-behind 5-4 triumph over Michael Smith.
The Englishman led 3-0 and missed a dart at double top for the match in the deciding set, before Van Barneveld made it over the line to remain on course for a sixth world title - four of his previous five wins having come in the BDO Championship.
Peter Wright became the first player to take a set off Lewis at this year's tournament, but it was scant consolation as the two-time world champion sent Wright packing with a convincing 5-2 win.
Lewis shot to a 3-0 lead before Wright took the fourth and, from there, the two traded sets as the former prevailed thanks to a cool performance, booking a semi-final clash with Van Barneveld.
Anderson underlined his status as the tournament favourite with a superb performance in a 5-1 thrashing of James Wade.
As Wade struggled badly, Anderson averaged 105.25 and came within a whisker of pulling off a nine-dart finish when an attempt at double 12 brushed the wire in set two.
Next up for Anderson is 2006 BDO champion Klaasen, who edged out Alan Norris 5-4 to become the first to player to win their next match after knocking Phil Taylor out of the tournament.
Norris also missed a shot at double 12 for a nine-darter as he performed strongly in defeat.