It was a good day for the Irish at the English Open as both Aaron Hill and Mark Allen booked their spots in the last 32 in Brentwood.
Hill once again downed a player ahead of him in the rankings with a 4-2 win over the world number 26. The Cork man, who made a 147 in his opening round win over Yao Pengchang, raced into a 3-0 lead with breaks of 50 and 58.
Maguire, though, showed his steely side to win the next two frames, and he looked to be on course to force a decider, only to break down on 60.
Hill, who has raced up to 26 in the one-year ranking list after a bright start to the 2025/26 season, held his nerve to knock in a break of 68 to win the frame on the pink.
Next up for the 23-year-old is a date with Ali Carter in the last 32.
Things were more straightforward for Allen, who knocked in breaks of 78, 67 and 54 to see of Scott Donaldson by four frames to one.
The Antrim man will face Stuart Bingham tomorrow night.
Elsewhere, world number one Judd Trump powered into the fourth round with 4-0 whitewash of Michael Holt.
After taking a tight opening frame, Trump eased through with breaks of 107 and 130 along the way in Brentwood.
World champion Zhao Xintong was also a convincing winner, making three centuries in a 4-0 defeat of India's Ishpreet Singh Chadha.
Xiao Guodong, the recent Wuhan Open winner, beat fellow Chinese player Gong Chenzhi 4-0 and defending champion Neil Robertson overcame Sunny Akani of Thailand 4-1.
Additional reporting: PA
