The three-wicket triumph was the reward for an outstanding all-round team performance in the Premier Division clash but, in the end, it all came down to Wanford.
The all-rounder, batting at No.9, went to the crease with Chesterfield, chasing 247 for victory off 50 overs, needing 10 to win off 11 balls with just three wickets left.
From the previous delivery Chesterfield had suffered what could have been a crucial setback when Ben Lodge, who had smashed a swashbuckling 38 off just 20 balls, was caught attempting another big hit.
Wanford played his first delivery from seamer Spencer Hayes defensively before turning the next to long leg and running two with Reece Johnson.
Wanford then drove a boundary before drilling the next delivery straight for another four to seal the win with seven balls to spare.
Chesterfield finished the game with a flourish and they began it in the same way.
After they put the home side in to bat, Muhammad Zaroob took two wickets in the opening over.
Hayes tried to hit the first ball into the leg side, missed and was lbw.
Scott McNeill left the final ball of the over but it swung back into him and bowled him.
That flying start helped Zaroob and his opening partner Johnson, who conceded only 12 runs off his 10 overs, to keep a tight grip on the scoring rate in the early stages.
Luke Thomas (68) and Connor Marshall (105) brought the hosts back into the game with a fourth-wicket stand of 136, which formed the backbone of their total of 246-7.
Zaroob struck again in his second spell to finish with figures of 4-45.
Luke Westwell and skipper Harry Wilmott gave Chesterfield a cracking start with an opening stand of 64 in 14 overs before Wilmott fell for 33.
Westwell went on to make a highly creditable 81 but, when he and Jordan Lemon fell in quick succession, Chesterfield were 195-6 with only six overs left.
Lodge, who has great power of shot, swung the equation back in their favour with the perfect innings for the situation.
He smashed a huge leg-side six in the 47th over, which yielded 11 runs, and added two more maximum blows in the 48th, which brought Chesterfield a bumper tally of 17 runs.
Lodge fell to the next ball but Wanford ensured that Chesterfield had a day to treasure.
It was only their 10th success in 47 Premier Division games between the sides.
They are fifth in the 12-team table on 105 points, 34 behind leaders Ockbrook & Borrowash.