Former skipper Ian Uttley and Neil Harvey were the heroes for the visitors, who pushed an Old Crossleyans side beaten at Sowerby SP back to the foot of the table.
Uttley was bowled by Jamie Cowens four short of a century as the Rams made 236 for nine, Joe Hammond (40) helping him add 82 for the third wicket.
Michael Wild hit the stumps three times as Royd began their reply but home captain Jon Lord made 91 not out to spearhead the home side's run chase. He added 65 with Cowens (44) and 94 with Zahid Mahmood (34) to make 'Royd favourites at 197 for four with plenty of overs left.
Young Tom Belfield grabbed a couple of wickets to raise Southowram hopes before Harvey, better known for his batting than bowling, mopped up the last four wickets for the addition of 21 runs.
Mytholmroyd, who play Booth in next Sunday's cup final at Sowerby Bridge, finished 10 runs short of victory with Lord left high and dry.
They lost fourth place to Jer Lane and fell further behind top three Blackley, SBCI and Sowerby, who all won.
Craig Taylor made 100 not out as Blackley beat visitors Triangle by 97 runs and extended their lead from 11 to 12 points with seven rounds of fixtures left.
Having reached 70 for one, Blackley lost three wickets for one run but Taylor rescued the situation and received good support from hard-hitting Tom Greenwood (34) and David Townsend (31 no)
Blackley finished on 288 for six and their main strike bowlers, James Watson (five for 54) and Greenwood (four for 41), ensured that was always going to be out of the visitors' reach.
Triangle were 92 for six but Christian Silkstone's 80 at least helped the visitors reach 188 and bank maximum batting points.
Jamie Summerscales made 112 as second-placed SBCI picked up nine points away to another in-form side, Northowram Hedge Top.
Summercales helped the visitors to 237 for nine and Northowram, only 77 for four midway through their overs, had Andrew Gardner to thank for maximum batting points. He made a hard-hit half century as the hosts finished on 190 for seven.
Gavin Clarke's 42 not out tipped the scales Sowerby's way after they had been 91 for five chasing Old Crossleyans' 166 for eight.
Anjam Hussain top scored with 33 and took three wickets for the visitors but Sowerby ended a three-match losing sequence with a three-wicket success worth eight points.
Chris Ramsden top scored with 46 and Matthew Jordan made 35 not out as Jer Lane batted solidly to reach 228 for eight at home to Sowerby Bridge.
Bridge were 40 for five before a century stand between skipper Paul Smith (70) and Chris Whitehill (36) helped them to 188 for eight.
Booth continue in superb form and blitzed troubled champs Warley by 155 runs.
They were asked to bat on a damp wicket at Booth and their innings was built around a superb partnership between the Laycock brothers. Richard hit 70 but star of the show was elder brother Robert who belted his third century of the summer with nine sixes. Robert was out for 103 off the last ball of the innings.
Able support was given by gloveman Rob Cockroft, with a typically agricultural 31 off about 10 balls. Usman Saghir bowled well for Warley with five for 80
Needing 252 for victory, Warley were in disarray at six for four, Richard Laycock and the hostile Nigel Horsfall making early inroads into flimsy batting.
The only resistance came from Brad Venter (26) and Craig Helliwell (29) but Helliwell's wicket triggered the rest to fold with Richard Laycock returning to complete another five wicket haul as Warley were dismissed for 96.

Points: Blackley 126, SBCI 114, Sowerby SP 112, Jer Lane 108, Mytholmroyd 105, Booth 103, Northowram HT 90, Sowerby Bridge 89, Triangle 89, Warley 85, Southowram 77, Old Crossleyans 72.