After being put in and losing Tim Robinson without a run on the board, Northants’ David Willey was then dropped on nought with Sam Wood parrying the ball over the rope for six.
He went on to make 27 with Bopara scoring 53 from 40 balls and Saif Zaib smashing 30 from 18 balls as the Steelbacks reached 100-2 in the 11th over.
They collapsed to 129-7 at the start of the 15th before Luke Procter and Ben Sanderson steered them to 171-7.
There were two wickets apiece for England’s Josh Hull, Logan van Beek and spinner Josh Thomas, who is on a short-term loan from Somerset.
Rishi Patel also fell without scoring to start the Foxes reply but Shan Masood and Sol Budinger added 71 inside seven overs before Masood was strangled down the leg side for 25 and Budinger holed out for 40 from 22 balls soon after, both off George Scrimshaw.
Ahmed and Louis Kimber guided the Foxes to 100-3 in 11 overs but Kimber (17) was bowled by Scrimshaw who ended with 3-33, leaving Ben Cox (21* from 10) to join Ahmed to see the hosts to the line.
The England all-rounder hit three sixes in his 30-ball unbeaten 52 not out.
At Derby, Worcestershire made it back-to-back wins to move within four points of the top four.
They might have been regretting choosing to bat first when they fell to 10-4 in the third over, with Zak Chappell (3-26) in fine form, however Roderick made 71 from 59 balls and steadied the ship with Ethan Brookes (43 from 26) before a late flurry from Ben Dwarshuis (33* from 18) and Tom Taylor (14* from five) saw the visitors post 174-6.
Despite two early sixes from Caleb Jewell (16), the Falcons lost wickets at regular intervals and although 41-year-old Madsen hit 10 fours and cleared the ropes twice, his side were unable to keep up with the required rate thanks to some stifling bowling.
When Martin Andersson was run out by Adam Hose with 28 still needed from 13 balls the game was up and Madsen was left on 77 from 53 balls as the Rapids saw it out.
