The Scot defeated Alfie Burden 5-1 to cement his spot in the rankings’ top 16 at the expense of Ding Junhui, who now needs to win three qualifying games in Sheffield next week to confirm his participation in the World Championship.
Ding turned 29 on the day he discovered Maguire’s run to the semi-final meant he now faces a tricky route to the main draw in the Steel City.
“I don’t think I’ll be his best friend right now,” Maguire said.
“I knew coming into the match it was me or him. To have to win three matches to get to the Crucible is very tough and he has got the short straw.
“It will be a shame for the World Championship if he doesn’t make it. Those three matches will be tough and it’s by no means certain that he will qualify.”
Maguire beat four players ranked outside of the top 32 to advance to his first last-four berth in a ranking event in nine months and, having been tied at 1-1 with Burden before winning the final four frames, he admitted there were plenty of nerves given what was at stake both for this tournament and the event in Sheffield.
“I’m just over the moon. I don’t think I have felt pressure like that before,” the 35-year-old added.
“All day I have been feeling it because it was such a big match.”
Maguire’s semi-final opponent will be Judd Trump, who came from 3-2 down to defeat Mark King 5-3.
The other semi-final will pit John Higgins against Ricky Walden after they secured respective triumphs over Noppon Saengkham and Stuart Bingham.