The Gloucester cueman racked up three wins from four to top the fledgling group in the event's final group stage before the big-money all-winners finale later in the week.
Milkins registered wins over Stephen Maguire, Tom Ford and Andrew Higginson but lost his final encounter of the day to Ryan Day.
Hot on his heels were Dominic Dale and Stephen Maguire, that latter having entered the competition in Group Two.
In-form Ford, however, had the dubious honour of becoming the first player in the event's six-year history to forfeit a match - his opener against Higginson - after he turned up late to Crondon Park Golf Club due to a missed flight and a long car journey.
The remainder of the round-robin matches will be played out on Tuesday before the play-offs begin ahead of Wednesday's finale.
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.
John Higgins, Martin Gould, Ding Junhui, Barry Hawkins, Mark Allen and Ali Carter have already made it through to Wednesday and await the winner of Group Seven.
Group Seven results day one:
Stephen Maguire 3-0 Marco Fu
Ryan Day 2-3 Dominic Dale
Andrew Higginson 3-0 Tom Ford (W/O)
Robert Milkins 3-1 Stephen Maguire
Marco Fu 3-1 Ryan Day
Dominic Dale 2-3 Andrew Higginson
Tom Ford 0-3 Robert Milkins
Stephen Maguire 3-0 Ryan Day
Marco Fu 3-1 Dominic Dale
Andrew Higginson 1-3 Robert Milkins
Ryan Day 3-0 Robert Milkins
Tom Ford 1-3 Dominic Dale