The Scotsman started the day in blistering style with whitewash 3-0 victories over Rickey Walden and Ryan Day before edging out Martin Gould 3-2.
Barry Hawkins also had three wins on the day but played in four matches. He defeated Gould, Walden and Peter Ebdon but was defeated by Joe Perry.
The round-robin stages conclude on Tuesday before the group play-offs in the evening.
Twenty-five of the world's top players are competing in the Premier League qualifying tournament.
Seven groups of seven players produce seven winners who play in one further group in March to determine the winner who will play in the 2013 Premier League.
In each group, the top four players from the round robin stage will contest the semi-finals and final over the best of five frames.
The players coming sixth and seventh in the group will be relegated and will not feature in any further group matches and therefore three players will leave and be replaced by a further three players.
Barry Hawkins 3-0 Peter Ebdon
Martin Gould 3-0 Ryan Day
Barry Hawkins 3-1 Ricky Walden
Ryan Day 3-1 Joe Perry
Stephen Maguire 3-2 Martin Gould
Ryan Day 3-1 Peter Ebdon
Ricky Walden 3-1 Martin Gould
Joe Perry 3-1 Barry Hawkins
Joe Perry 3-2 Peter Ebdon
Stephen Maguire 3-0 Ryan Day
Barry Hawkins 3-0 Martin Gould
Stephen Maguire 3-0 Ricky Walden