Sam Hain struck a brilliant 93 to take the Bears within an inch of victory.
Saif Zaib hit a blistering 86 off just 41 balls with eight fours and six sixes. He shared a partnership of 72 in almost seven overs with Ravi Bopara (19) to propel Northamptonshire to a formidable total of 197 for six.
Steelbacks skipper David Willey struck immediately in the run chase taking two wickets in the opening over, including dangerman Moeen Ali first ball, as the Bears slumped to 11 for three.
But a magnificent 93 from Sam Hain off just 60 balls (10 fours, three sixes) took the match into the final over with the Bears still very much in the hunt.
Hain shared a partnership of 92 in nearly 10 overs with Jacob Bethell who hit 50 off 31 balls (two fours, four sixes) as the visitors bounced back from the early fall of wickets.
