Maguire began the 2009–10 season by winning the first event of the Pro Challenge Series defeating Alan McManus 5–2 in the final. He followed this by reaching the semi-finals at the 2009 UK Championship by defeating Michael Holt 9–6 in the first round, Stuart Bingham 9–3 in the second round and Peter Lines 9–3 in the quarter-final, before he lost to Ding Junhui 5–9. At the invitational Masters event in 2010, he beat Mark King 6–3 in the first round and Ryan Day 6–1 in the quarter-finals, but lost 3–6 in the semi-finals against Mark Selby. He also reached the semi-final stage at the Welsh Open. He defeated Dominic Dale 5–4 in the first round, Barry Hawkins 5–1 in the second round and Mark Williams 5–1 in the quarter-finals, but he lost 3–6 against defending champion Allister Carter. In the 2011–12 snooker season, Maguire's season started poorly with first round exits at the opening two ranking events of the year, the Australian Goldfields Open and the Shanghai Masters. At the UK Championships he defeated Stephen Hendry and John Higgins to set up a quarter-final with world number seven Judd Trump, which Maguire lost 6–3. He made three Century breaks during the tournament, including a 144, which was the highest of the event.