Eagles coach Flournoy has led Eagles to 14 pieces of silverware since his arrival in 2001
Newcastle Eagles completed a clean sweep of all four BBL titles this season with a 71-62 win over Leicester Riders in the Play-Off final.
Charles Smith, who led the Eagles' scoring with 21 points, was named the game's Most Valuable Player.
Leicester made the better start to both halves, but the Eagles' big-game experience told in the second half.
The Eagles added the Play-Offs title to the Cup, Trophy and league titles they have already won this season.
In all, they have won five play-off titles and 17 of the 28 BBL titles on offer during that period under player-coach Fab Flournoy.
Spurred on by Great Britain captain Drew Sullivan, Leicester started aggressively and finished the first quarter with a 10-0 run to lead 21-12.
Newcastle 71-62 Leicester
- Newcastle Eagles: Smith 21, Gause 13, Defoe 10
- Leicester Riders: Sullivan 18, Hardy 12, Wierzbicki 11
Newcastle recovered their poise in the second quarter with the help of point guard Paul Gause and tied the game 31-31 just before the half-time interval courtesy of a Darius Defoe dunk.
Gause went on to score 13 points and Defoe added 10, while Sullivan had 18 points for Leicester but lacked consistent scoring support from his colleagues.
Leicester scored the first six points of the second half but Newcastle overhauled them and led 63-53 going into the last five minutes of the game after a three from Andy Thomson.
The Eagles held on to win thanks to baskets from Gause and Defoe in a scrappy end to the game, in which both teams missed several chances to make a decisive run.