Sheffield, who have led the League since early November, lost the chance to claim the championship this weekend with Saturday night's 96-82 defeat against Manchester Giants.
The Sharks' 93-75 victory against Thames Valley last night still left the title race open, at least until Sheffield and the Tigers meet again on Wednesday, at Bracknell. Sheffield could yet need to win their final game, against Doncaster Panthers next Sunday, to be sure of the championship.
Tigers' challenge hung in the balance as they trailed Chester Jets 89- 88 with three minutes to go. But Peter Scantlebury inspired a 10-0 burst which turned the game for Thames Valley.
London are certain to maintain the pressure tonight with victory over Sunderland Scorpions.