Fu produced a stunning recovery to fight back from 2-0 down against Allen, who missed a shot at the blue in the third frame that would have given him the title. In fact, Fu needed a snooker to stay in the event and from an almost impossible position he achieved a magnificent win.
"Qualifying for the Premier League is a very special moment for me as everyone wants to play in the league," said Fu, who beat Mark Williams in the 2003 Premier League final. "Only the top players can play in it and with it being live on television it is a very prestigious competition.
"I was very lucky to win the third frame and when you're one snooker down you don't expect to win. I was lucky I got the snooker, he surprisingly missed it and I made a good pink to win the frame.
"That was the turning point in the whole match as Mark was a little bit disappointed. He was expected to win but he didn't play that well from then on and I made two good breaks to win the match. Sometimes you need a bit of luck and not only to play well."
Allen won the opening frame by 75-31 but had some nervous moments when he missed a frame-winning pink into the centre pocket. However, that error did not prove costly as Fuís failure to pot the green handed the frame to the Northern Irishman.
It was a similar story in the second as Allen was not punished when he potted the blue ball but then saw the cue ball vanish into a pocket. The frame ended 72-35 in Allenís favour and he was now only one frame away from the trophy.
Allen stormed to a break of 53 in the third and was in sight of the title, but a loose shot let in Fu, who made 38 before he lost position and had to play safe. A fine long pot on the green put Allen back in pole position but the potential match-winning pot, a slow-rolled blue, was left hanging in the jaws of the pocket.
Fu needed one snooker, which he got and he stole the frame by 64-61 to keep his hopes alive. He then made a break of 94 to take the match to 2-2 and leave a one-frame shootout for the title.
Allen again had another opportunity but was left slumped in his chair after missing a straight-forward red. He did not get back to the table as Fuís break of 134 gave him the victory.
Earlier, Fu had made light work of group winner Stephen Maguire in what could have been a tough encounter. He rattled in consecutive breaks of 111, 94 and 95 to complete a quick 3-0 win.
Allen, by contrast, endured a real struggle with Neil Robertson. The Australian came out the traps with a break of 116 but the Northern Irishman stuck with him and a run of 51 in the decider saw him over the line.
Championship League Snooker, which has been broadcast live on a number of betting websites, featured 25 of the gameís best players competing over three months. Seven qualifying groups took place with the winners of each one advancing to the Winnersí Group.
Played at Crondon Park Golf Club in rural Essex, Championship League Snooker is produced exclusively for live streaming on internet betting sites throughout the world.
Fu joins 2009 Premier League Champion Shaun Murphy in the 2010 PartyCasino.com Premier League Snooker competition along with the 2010 World Champion. Four players will be awarded Premier League wild cards.
Beginning on September 2, the Premier League takes place over ten Thursdays before the finals at the end of November with each match broadcast live on Sky Sports.
Stephen Maguire 3-2 Mark Allen
70-28, 6-60 (Allen 38), 70-14 (Maguire 70),1-69 (Allen 41), 80-0 (Maguire 80)
John Higgins 1-3 Neil Robertson
138-0 (Higgins 138), 40-69 (Robertson 32), 30-81 (Robertson 81), 39-72 (Higgins 32, Robertson 56)
Marco Fu 3-0 Jamie Cope
103-26 (Fu 103), 66-30 (Fu 48), 58-57 (Cope 48)
Judd Trump 0-3 Mark Allen
5-64 (Allen 57), 0-79 (Allen 75), 23-99 (Allen 95)
John Higgins 0-3 Jamie Cope
1-58 (Cope 30), 36-62 (Cope 32), 35-77 (Cope 35)
Stephen Maguire 3-2 Neil Robertson
80-45 (Maguire 80), 24-67 (Robertson 43), 0-93 (Robertson 93), 68-1 (Maguire 35), 72-0 (Maguire 65)
Judd Trump 2-3 Neil Robertson
0-117 (Robertson 115), 0-128 (Robertson 100), 82-6 (Trump 73), 57-14 (Trump 49), 1-73 (Robertson 49)
John Higgins 3-2 Mark Allen
42-66 (Higgins 37, Allen 36), 61-24 (Higgins 44), 0-71 (Allen 71), 94-0 (Higgins 94), 82-0 (Higgins 82)
Stephen Maguire 3-0 Marco Fu
118-0 (Maguire 118), 63-25 (Maguire 37), 79-36 (Maguire 38, Fu 36)
Stephen Maguire 0-3 Marco Fu
0-111 (Fu 111), 7-94 (Fu 94), 0-103 (Fu 95)
Mark Allen 3-2 Neil Robertson
0-136 (Robertson 116), 72-22 (Allen 51), 71-4 (Allen 59), 35-82 (Allen 35, Robertson 66), 60-21 (Allen 51)
Marco Fu 3-2 Mark Allen
31-75 (Allen 38), 35-72 (Allen 38), 64-61 (Fu 38, Allen 53), 94-26 (Fu 94), 134-6 (Fu 34)