Moore shot 1-under 71 to tie the tournament scoring record with a 20-under-par 268 total. Maginnes shot 68, but could only watch as Moore capped his roller-coaster round at the last.
'All that work that you put in on the range and the putting green and basically it comes down to about three seconds,' said Moore, who survived a playoff in the Monday qualifier just to make this week's field.
'This week was probably the first time in more than two years that I could stand over the ball and feel comfortable about where it's going. It's the first week I've felt in control. It's nice now - I can make a schedule.'
More from Moore on his win
Moore collected $76,500 for his first win in just his fourth career tour start. He now has fully exempt status on the Buy.Com Tour, after 'plugging along' on mini tours around the world.
Moore led by one entering the final round at the Dominion Club in Glen Allen, Va., and birdied three of his first four holes. However, he came back to the field with four bogeys over his next nine holes.
Maginnes, who will defend next week at the SAS Carolina Classic, took the lead with a two-putt birdie at the par-5 18th and stood waiting for a possible playoff.
It would never happen.
Moore hit a 6-iron second shot 15 feet right of the hole, just off the putting surface at the last. He then converted the eagle effort for victory.
Jay Delsing (68) and Jason Buha (72) tied for third, three back of Moore.
Final Results from the Buy.Com Richmond Open