Mirza’s explosive five for 18 ripped the heart out of Honley’s bid to put pressure on the Premiership leaders from the Colne Valley.
Delph were dismissed for only 136 at Far End Lane, with Harlon Haye (3-56), Ritchie Howarth (4-41) and Enamul Haque jnr (3-32) proving too accurate.
But they were no match for Mirza who, after Bilal Khiljee and Kyle Hogg had made early inroads, smashed through the Honley order.
It was their first defeat in two months and enabled Golcar to extend their lead to nine points at the top of the table with a five-point four-wicket win at home to Shelley.
Tim Welsford was the Golcar hero, taking six wickets and scoring 38 after Matt Freidlander (68no) had anchored the Shelley reply.
Barkisland went second with a crushing seven-wicket win at Meltham, who were dismissed for 142 thanks to Matt Steers taking four for 25 and Darren Robinson four for 37.
Robinson then steered the Calderdale side to victory with an unbeaten 35 after Paul Winrow (43) and Dave Weston (30) had done well.
Elland are now level on points with Delph, just one adrift of third-placed Honley, after a seven-wicket success at Clayton West, for whom Paul Van Den Berg had 82 not out in their 201-7. Yorkshire’s Ajmal Shahzad (73), Ryan Robinson (61) and Cameron Borgas, with an undefeated 49, saw Elland home.
Emley remain bottom of the table after a five-wicket home loss to mid-table Skelmanthorpe, who have signed the experienced Shahid Mahboob once again.
Asif Zakir was the backbone of the Emley tally of 179-7 with 79 while Nick Wilson and Craig Stratford each contributed 33. Mahboob had three of the wickets to fall on his return to Drakes League action, while Andrew Clarke and Scott Dyson had two apiece.
While Mahboob failed with the bat, Max Joice (30), Dyson (35) and James Dollive (69 not out) took Skelmanthorpe to victory with three overs to spare.
Micklehurst won by seven wickets at Holmfirth, where Dennis Lonergan hit 71 to go past 1,000 runs for the season.
Tim Rees was the hero as Shepley stayed within striking distance of third place with a seven-wicket win at Lascelles Hall.
John Booth batted through for an undefeated 98 as the Hall totalled 178-7, Craig and Danny Glover taking two wickets each, before Rees (85 not out) shared in a second-wicket stand of 112 with opener Tom Denton (44) to make sure of victory in the 43-over match.
Yorkshire academy prospect Charlie Roebuck was the star of the Inter-Conference programme with a fine undefeated 136 in an overwhelming victory against Frank Platt Conference bottom side Lepton.
Roebuck had 17 fours and five sixes in his ton and shared in a fourth-wicket partnership of 141 with Joe Lumb Cup captain Jack Hargreaves (45), after James Houson had got them off to a solid start with 53.
The Oak’s 256-4 was always going to be too much for the home side and Lepton were shot out for just 82 in 24.5 overs thanks to five for 42 from Ben DeAraugo.
Slaithwaite remain 13 points clear in the Frank Platt after Chris Kilner (4-8), Kana Vaghela (3-27) and Mark Mitchell (2-20) dismissed Rastrick for 59 and they were able to secure a nine-wicket win in the 45-over game.
Cedar Court leaders Scholes were well beaten at Marsden and have had their lead cut to just seven points by Kirkheaton, who took five points at Kirkburton.
Andy Alsop had five for 64 for Scholes as Marsden totalled 141-8 in the 35-over game, then Simon Robinson (6-32) and Peter Lombard (4-24) shot out Scholes for 95 despite a bright 48 from opener Tom Brook.
Dale Winterbottom led Kirkheaton’s victory parade with 82 (seven fours and five sixes) and three for 40 as Burton closed on 151-9 in reply to 215-7. Alex Slack had eight fours and a six in his 50 for Kirkheaton, who were also indebted to Ibrar Younas with five for 37.
Paddock scored a fine six-wicket win at Thongsbridge, Waqar Rafiq taking five for 39 and then Taimur Shah hitting 52 as they overhauled the Bridge’s 137 all out.
And there was a hat trick for Kala Khan of Almondbury in his four for 56 as they defeated Linthwaite by five wickets, Jawad Hamid the batting hero with eight fours and four sixes in his 68 not out.