Maguire won the title back in 2004, beating David Gray 6-1 in the final, but he produced an even more dominant performance in the 2019 semi-final against Allen.
The Northern Irishman, himself a two-time finalist at the tournament, made just one break of more than 50 in the entire match and could only watch as Maguire made his second century of the match to seal a 6-0 drubbing.
“I’m a bit shell-shocked really. I don’t feel I was involved in that match at all. He was flawless from start to finish," Allen said.
“He missed one ball of any note in the match and I didn’t think I did that much wrong but I’m standing here having beaten 6-0.”
‘Devastating’ – Maguire reaches final in York
Against Nigel Bond in the quarter-final, Allen lost the opening mini-session 3-1 but he would not have thought it could get worse against Maguire - but it did.
Allen was caught cold again and Maguire was ruthless, denying the Northern Irishman a single point in the first two frames and scoring heavily.
His 95 in the opening frame was nearly flawless until a tricky red down the cushion defeated him, but he would not be denied the first century of the match in frame two.
Another long pot missed by Allen allowed him another opportunity and again, he was more than happy to cash in, amassing 129 points to make it 224 unanswered points to open the match.
Allen looked like he would finally get a frame on the board when he made 67 in the third, only to miss with frame ball beckoning.
O'Sullivan: Personal reasons not behind Masters absence
Maguire was not in the sort of form to need more than one invitation and took a 3-0 lead with a break of 72 before ensuring Allen walked out of the arena for a break without a frame to his name.
Having been "nilled" three times out of four, Allen would have been forgiven for being rusty and it showed when he took on an ambitious plant with 38 points already to his name.
Maguire eventually moved far enough ahead to make it 5-0, another half-century to his name, and a whitewash beckoning.