They ended a run of three defeats in Division One by landing a 49-run win. Sam Fawcett played a key role with bat and ball in a triumph which sets up a crucial clash with promotion-rivals Sawley at Queen's Park on Saturday.
Fawcett opened after Chesterfield were put in and held together the first half of the innings. Starting steadily and gradually increasing the tempo, he shared a second-wicket stand of 59 with Luke Westwell (19). Fawcett made 67 but Chesterfield looked in trouble on 109-6, Joe Treece taking 4-33. But Ben Lodge made 39 off 40 deliveries and James La Brooy and Harry Wanford added an invaluable 26 for the last wicket, Chesterfield all out for 203.
Muhammad Zaroob struck twice to reduce Ilkeston to 46-3 before a fourth-wicket stand of 65 between George Moulds (40) and Tom Brandrick (24) put the hosts back in charge.
But Fawcett put a brake on the scoring in his 12-over spell of left-arm spin. He bowled four maidens, conceded just 23 runs and, crucially, broke the big stand by having Brandrick caught by wicket-keeper Lodge.
From then on Chesterfield had the edge with La Brooy increasing the pressure with a spell of 2-21, the bowlers backed up by some smart fielding.
Left-arm seamer Reece Johnson struck with his second delivery and hastened the end by taking 3-4 as Ilkeston were all out for 154.
Chesterfield are fourth in the table on 294 points, 13 behind Sawley who hold the second promotion spot.
They need to beat Sawley and Langley Mill United in their final two games and hope third-placed Morton Colliery lose at least once.
*The seconds still have a chance of promotion thanks to a five-wicket victory over their Ilkeston counterparts at Queen's Park.
All-rounder Ewan Westwell was in fine form in the Division Four North clash.
Westwell (2-17) and Jacob Madin (3-16) reduced the visitors to 29-5 after they were put in.
Skipper Matt Whinfield (36 not out) led a mini-revival but they were bowled out for 98. Alex Fowkes took 2-26 before launching the Chesterfield reply with a fluent 17.
Westwell, batting at three, then took charge. He played himself in carefully before launching an array of drives and pulls. He made 44 off 41 balls before being caught on the leg side.
Only eight more runs were needed and Chesterfield reached their target in the 20th of their 45 overs.
Chesterfield are third in the table on 298 points. To go up, they need to win their final two matches and hope second-placed Belper Meadows do not land another victory. On Saturday the seconds are at Hollinsend Methodist.
*The third team drew at Matlock and Cromford Meadows in Division 10 North.
Chesterfield declared on 248-6 and the home team closed on 112-8. The thirds next host Butterley United seconds at Holmewood.
*Chesterfield's Sunday side lost by nine wickets at Mansfield & District League leaders Welbeck.
Johnson hit 51 and Josh Sharratt 42 in Chesterfield's 154 all out but Welbeck reached their target in the 27th over.
This weekend the Sunday side travel to Farnsfield.