Outlaws won a rain-affected match at Edgbaston by eight wickets on the Duckworth-Lewis method.
Outlaws restricted Birmingham to just 119 for nine in an innings that produced four fours and no sixes.
And opener Joe Clarke led the way in reply with an unbeaten 47 as the Outlaws reached 86 for two after only 11 overs before rain forced the game to be abandoned.
The Bears had no answer to the Outlaws attack with pace bowler Luke Wood the pick with figures of three for 24 – including a wicket from the final ball of his first over of the night.
That was Wood’s second first over scalp in successive games and set the tone for what was to come.
Spinners Matt Carter and Imad Wasim claimed two victims apiece in key spell .
Dom Sibley provided some signs of recovery for Bears with a 23-ball innings of 25 – including four boundaries – before he fell to Wasim when Carter caught him at short third man to reduce Bears to 35-2.
And the introduction of Carter and Pakistani all-rounder Wasim had Birmingham tied in knots.
But Sam Hain flew the flag for Bears before cruelly falling one short of his half century.
Hain departed when Birmingham captain Jeetan Patel drove off the bowling of Harry Gurney and managed to deflect the ball on to the stumps. That saw Hain dismissed for 49 from 47 balls.
Wood finished as he had started and took the ninth wicket – Oliver Hannon-Dalby – for one.
In reply, Outlaws cut loose in the third over with Clarke hitting 24 runs including two sixes and three fours – and failing to score from the other delivery.
Nottinghamshire raced to 48 without loss after four overs.
But, with more rain falling, Outlaws lost their first wicket when Hannon-Dalby had Alex Hales caught behind for 11 in his first bowling spell.
Outlaws made quick progress towards their target despite losing a second wicket with the score on 80 when Ben Duckett was bowled by Patel for 16.
But the rain became too much and the players were forced off before an Outlaws victory was confirmed.