Mark Allen was pleased with the way he coped with Ronnie O'Sullivan after beating the seven-time Masters champion 6-1.
O'Sullivan had won the tournament in each of the last two years and had thrashed Marco Fu 6-0 in the first round earlier in the week.
However, Allen produced a sublime display, compiling one century break and three more over 50 as he beat O'Sullivan for the first time since the 2011 Masters.
The Ulsterman will play either John Higgins or Ryan Day at Alexandra Palace in the semi-finals on Saturday evening.
"I played pretty well to go 5-1 up, my safety was good, my long potting was good," said Allen afterwards.
"You can't go out there and be scared of Ronnie. I play more aggressive against him, I can't be bullied by him.
"It was an extremely tough match but I was up for it. It's always an occasion playing Ronnie. I came here to win the tournament and I'm only halfway there. If I play as well as the first two matches then I've got a great chance."
Meanwhile, Kyren Wilson eased to a 6-1 victory against Mark Williams on Thursday and will play either Judd Trump or Shaun Murphy in the semi-finals.
"I'm very pleased to get through," Wilson said after his victory. "I believed from the start that I could win this. I have put in a lot of good performances this season, getting to a couple of finals and scoring heavily. I feel I am improving."
Wilson is 6/4 to win the 2018 Masters outright, while Allen can be backed at 11/4, Trump at 1212/1 and Murphy at 1212/1.
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