Birmingham 154 for 5 (Chopra 52, Crook 3-30) beat Northamptonshire 153 for 6 (Wakely 51*, Hannon-Dalby 3-36) by one run
Reigning NatWest T20 Blast champions Birmingham booked a home quarter-final this time round by beating Northamptonshire by one-run in a thriller at Edgbaston.
Set a target of 154 for a victory which would have secured their own place in the last eight, Northamptonshire needed 23 from the final over, from Recordo Gordon - and almost got them. But despite the heroics of Alex Wakeley and Rory Kleinveldt, who hit 29 from just 11 balls, they fell just short so must win their last game, at home to Durham on Friday, to be sure of qualifying.
Birmingham's hopes of a valedictory Brendon McCullum masterpiece in his last home game for the club floundered when he perished for just 26 but captain Varun Chopra's 54 from 48 assured his side a decent total, albeit one that looked a little below par.
The loss of early wickets undermined the Northamptonshire pursuit and it was only down to that spectacular last over that they came so close.
Northamptonshire chose to bowl and face the threat of McCullum straight away, a decision they might have questioned when he cracked four of his first ten balls for four. That was as far as his boundary count went though before he was superbly caught at point by Kleinveldt off Steven Crook.
It was left to youngster Tom Lewis to show McCullum how to clear the ropes, but that blow was one of only two sixes hit by the Bears as the Northamptonshire seamers, led by Azharullah (4-0-24-1), bowled an excellent length. Chopra hit five fours and a six before becoming one of three victims for Crook.
On a good batting track, the Steelbacks began their reply as slight favourites but lost early wickets. David Willey, Ben Duckett and Richard Levi all went for broke in the first six overs and sent up catches, the latter superbly taken by Lewis at deep midwicket.
Another fine opening spell by Rikki Clarke (4-0-16-0), providing more ballast to those who believe he is worth an England recall in limited-overs cricket, cranked up the required run rate and spinners Jeetan Patel and Josh Poysden maintained the pressure to send Northamptonshire into the last six overs needing 69.
That came down to 23 from six balls and when Kleinveldt clobbered the first two for six it was game on - but, with four needed from the last ball, Gordon held his nerve, just, and conceded only two to long-on.