They went into the game on the back of consecutive league and cup defeats and without opening bowler James Watson but their lightweight attack did them proud to help them re-establish an eight-point lead at the top.
Tom Greenwood removed Gareth Standeven without a run on the board and went on to return figures of five for 48 as Sowerby were dismissed for 125.
Gavin Hayes (38) helped Sowerby to 54 for two but the loss of four wickets for four runs left the home side in dire straits and they needed some determined batting from Martin Schofield (29) and some lusty blows from Reece Richardson (28) to score as many as they did.
Occasional bowler Reece Jennison weighed in with four for 46 but he and Dan Houldin departed with the score on five as Blackley began their reply.
David Milner became a second victim for Schofield with the total of 17 but Craig Taylor's 58 not out proved the game's crucial innings and Chris Overend made 36 as Blackley won by five wickets.
A defeat for third-placed Jer Lane, who fell victim to another inspired performance from Booth teenager Richard Laycock, was more good news for Blackley.
Laycock hit a sublime 133 as Booth rattled up a club record 379 for eight after Jason Gelder had sent them in.
Laycock hit 19 fours and six sixes in his third ton of the summer, which was quite a sedate efforts by his standards but full of delightful flicks, drives and his trademark effortless big hits.
There were other good contributions from evergreen Ian Sharkey (75), hard-hitting Andrew Truscott (45 no) and skipper Jim Mosley (31).
Laycock then followed up with five for 14 as Jer Lane folded from 75 for three to 120 all out in a game concluded quickly in spite of a rain break.
Nigel Horsfall, Ollie Collinge, Patrick Thomas also bowled well while Jonny Lister (31) offered the only real resistance before being caught down the leg side.
SBCI went above Jer Lane with a 20-run win at Southowram.
Safir Hussain dismissed seven of the first eight SBCI batsmen in a 20-over stint, having initially struggled to part openers Alex Kaye (58) and Jamie Summerscales (33), who had put on 70.
Southowram looked to have the upper hand when their visitors were 138 for nine but last pair Simon Wood (29 no) and Ollie Benson (25 no) added 56 precious runs and that made all the difference.
Chasing 195 for victory, home skipper Dean Crossley sped past 600 league runs for the season with 91 to leave the Rams sitting pretty at 128 for three.
However, Southowram slipped to 157 for nine with Crossley falling to spinner Ben Summerscales and Chris Punda's fourth wicket wrapped up victory for SBCI.
Southowram still picked up enough points to lift themselves off the bottom, above Old Crossleyans, but Northowram Hedge Top's easy win at Triangle means the bottom two are eight points adrift.
Sowerby Bridge's Lee Smith bowled a triple wicket maiden on the way to figures of five for 24 as the Crocs were dismissed for 131 at Walton Street.
Rain left Bridge needing 113, and 40 from Tim Helliwell and 35 not out from Lee Smith saw them home by five wickets.
Northowram's third league win of the season came courtesy of a good bowling performance to dismiss Triangle for 158 with slow bowler Adam Stocks and skipper Johnny Beecham collecting three cheap wickets apiece.
There was one moment of controversy when opener Neil Uttley was out for four. He was caught off a no ball but didn't hear the call and he was then run out as he set back towards the pavilion.
The visitors knocked off the runs inside 24 overs with 94 from opener James Little and 36 not out from Chris Metcalf.
Mytholmroyd repeated their earlier win over Warley in the battle of the last two champions.
Ian Shaw made 98 not out and Michael Midwood and John Rawson made 59 apiece to propel visitors Warley to 308 for four, a total reduced to 267 for rain.
'Royd, boosted by a great opening stand between Shahid Rashid (64) and Steve Senior (70), knocked off the runs thanks to skipper Jon Lord's unbeaten 54.
POINTS: Blackley 104, Sowerby SP 96, SBCI 87, Jer Lane 85, Mytholmroyd 82, Sowerby Bridge 78, Booth 73, Triangle 72, Warley 72, Northowram 66, Southowram 58, Old Crossleyans 57.