Derby beat Sheffield 81-80 at Moorways on Saturday and beat Birmingham 62-61 at the NEC over Birmingham last night, with the winning three-pointer scored two minutes from time by former Bullet Stedroy Baker.
Birmingham lost the chance to close in on defending champions and leaders Greater London Leopards, who lost 85-70 at Wembley last night against their greatest rivals, London Towers.
Leopards were hit by a fourth-quarter injury to their leading scorer Eric Burks, then missed six consecutive free throws while Towers built a 7-0 run to lead 67-59. Paul Deppisch hit two three-pointers to put London 13 points ahead.
Sheffield's defeat against Derby ended their title hopes, coming 24 hours after an astonishing 92-91 home loss against Crystal Palace.
Newcastle Eagles are level on points with Leopards, after beating Towers 90-80 and Worthing 107-84.
l Laszlo Nemeth's fate as England coach has been deferred for another two weeks, after he was suspended for criticising the English Basketball Association's former chief executive Steve Catton, who resigned last weekend.