Team Unicorn duo James Wade & Dimitri Van den Bergh will face off for a place in the BoyleSports Grand Slam of Darts Final later this evening.
James Wade remains on course to reach his third Grand Slam of Darts final after taking a 16-13 win over Damon Heta in a high-quality last eight encounter.
The 2010 and 2016 runner-up made a superb start to win the opening four legs without reply and also led 10-6 at one stage.
Australia's Heta, though, hit back to level the game after 26 legs as he searched for his maiden televised ranking semi-final, only to see the left-hander take three legs without reply to claim victory.
Legs of 15, 15, 13 and 11 darts from Wade saw him make a brilliant start and establish a ton-plus average which he would retain throughout the contest.
Heta pulled back to 4-3, but Wade denied him a chance to level with a key tops, and took out 152 and 101 as he moved into a 9-6 lead.
Tops moved Wade four legs clear once more, but 2019 Brisbane Darts Masters winner Heta showed his quality by finishing 108 and 142 to kick-start his response, before landing a ten-darter and a 101 finish as he pulled back to 13-all.
Wade, though, pinned double 16 for a 14-darter and then took out 96 to move 15-13 up, before a third-dart double two moved him into the last four.
"I'm so happy I won," said Wade, who also reached the European Championship final three weeks ago. "I did the right things at the right times of the game.
"Even though I was well in front and I was probably the better player for the majority of the game, I believe I was lucky.
"I thought he would get nervous and cave in, but he didn't - he showed a bit of class and showed his resilience and I was fortunate he missed a few shots.
"The 96 finish was massive - if I'd have missed that, I'd have lost the game. I've played in one or two games before and I know what wins and loses games, and at that point I thought it was enough to keep me in the game, not win me the game.
"It was quite a good game and the better player on the day won. I'm grateful to still be in the tournament and I'm looking forward to my next game. I've been there and done it and I'm enjoying myself."
Meanwhile Belgian star Dimitri Van den Bergh edged out Nathan Aspinall 16-15 in a final-leg shoot-out as he continued his bid to follow up July's World Matchplay triumph with another huge title.
Aspinall played his part in another epic contest, leading 11-8 at one stage and coming from 14-12 down to lead 15-14, only for Van den Bergh to finish the stronger and claim the game's final two legs.
"I'm so chuffed that I'm through," said Van den Bergh, who now plays Wade. "It was a proper emotional rollercoaster and I'm still in that ride.
"I kept battling and never gave up because today was a such a struggle. I lost the first three sessions 3-2 and went down 9-6, but I kept digging in and believing in myself.
"We didn't perform the way we can but at least I have a chance to improve in the next round, and I will learn from this quarter-final. It's a lesson for me but this week is going very well and I'm playing strong."
Van den Bergh opened the tie with six perfect darts but lost the first leg and trailed 2-1 before eight successive breaks of throw left Aspinall 6-5 up.
The Belgian held throw to level, but Aspinall finished double ten, 74 to break and double eight as he opened up a three-leg gap, which he retained at 10-7 and 11-8 despite Van den Bergh again throwing six perfect darts in one leg.
The Belgian finished 82, 130 and double four as he hit back to level at 11-all, and added another three straight legs as he moved into a 14-12 lead.
Aspinall, though, levelled as he punished four missed doubles from the two-time World Youth Champion, and fired in tops for a third straight leg as he moved 15-14 up.
Van den Bergh landed a 180 and posted double 16 to send the game into a deciding leg, in which Aspinall was left on 36 after landing a 180 only to see his rival pin double 18 for the win.
Monday November 23 (1900 GMT)
Simon Whitlock v Jose De Sousa
James Wade v Dimitri Van den Bergh
Best of 31 legs