Northamptonshire 155 for 6 (Cobb 48, Hughes 2-23) beat Derbyshire 140 for 5 (Durston 60, White 2-27) by three runs (D/L method)
Azharullah held his nerve to bowl a superb last over that gave Northamptonshire a three-run Duckworth-Lewis victory over Derbyshire in the NatWest T20 Blast North Group game at Chesterfield.
Derbyshire needed nine to reach a revised target of 144 in 18 overs but Azharullah conceded only five and bowled Scott Elstone with the final ball to keep Northants in the chase for a quarter-final place.
Josh Cobb top-scored with 48 out of 155 for 6 before heavy rain delayed the game by 90 minutes but despite Wes Durston's 60 from 39 balls, Derbyshire lost their way against disciplined bowling and remain bottom of the group.
"Azza has done it one several occasions for us, he loves the pressure and responsibility of bowling that last over and backs himself to get those yorkers in and he's a good man to have with the ball in his hand at the end," Northants head coach David Ripley said.
Derbyshire played well for much of the game after Durston won the toss for the fourth match running and restricted Northants to 20 from the first four overs before Richard Levi flicked Wayne White over square leg for the first six.
Josh Cobb pulled Shiv Thakor into the trees over long-on and although Durston checked the run flow by conceding only four from the seventh over, 17 came from his next with Cobb just clearing the leaping fielder at wide long-on.
Cobb drove Thakor for a straight six but the allrounder cut one back to have Levi lbw for 42 off the last ball of the 10th over and Durston removed Cobb in the next when he played across the line. When Alex Wakely chipped Alex Hughes to long-on, Northants had lost three wickets for 11 runs in three overs and Ben Duckett's attempt to clear the ropes ended in the hands of wide long-on in the 14th over.
Northants were in danger of disintegrating when Adam Rossington was superbly caught by Durston at cover and Rory Kleinveldt was the victim of extra bounce in a double-wicket maiden for White.
Derbyshire's bowlers did not concede a boundary in six overs until Steven Crook drove White down the ground but Rob Keogh swung Thakor for six before Crook pulled the third ball of the final over from Nathan Rimmington over long-on to take the visitors past 150.
But the storm which had been approaching finally broke over Queen's Park as the players were leaving the field and the game was delayed for 90 minutes before Derbyshire faced a revised target.
Derbyshire had not given away a single extra but Kleinveldt bowled two wides in the first over and Durston and Hamish Rutherford had the home side well on course at 43 without loss from the opening five overs. Durston swept Cobb for six over midwicket but the allrounder took a stunning running catch off Graeme White at long-on in the next over to remove Rutherford for 20 and Levi held an equally good one at short cover to send back Chesney Hughes without scoring.
Durston cut and pulled Cobb for boundaries before sweeping White for six and completed his 50 from 32 balls before White took a return catch off Wayne Madsen to keep Northants in the game. It was important for Derbyshire that Durston stayed but after he pulled Crook to deep midwicket, Derbyshire again came up short when the pressure was on.
Derbyshire's elite performance director Graeme Welch said: "We should have won that with 10 balls to spare but we haven't been winning these tight games so maybe it's lacking a little bit of belief and knowing how to win in tight situations."