Thornton are the surprise early leaders in the Spenser Wilson Halifax League, having dropped only one point in their opening three games.
Copley became their latest victims, put on the back foot by an excellent opening stand of 170 between Greg Soames (112) and Ross Carnall (70) on a cold but dry Saturday.
Chris Goulden did his best to get Copley into the contest, taking five for 58 to restrict the home side to 234 for eight.
However, Copley slipped to 140 for seven but Goulden hit an unbeaten 41 to salvage maximum batting points at 186 for seven.
The blood pressure has certainly been rising for the players and supporters of last season’s top two Booth and Warley.
The pair had fought out a thriller the previous Saturday - Booth won by one wicket - and were involved in nail-bitting finishes again.
Booth are second, one point behind Thornton, after scrambling a bye off the last ball to win a high-scoring derby at Mytholmroyd by six wickets.
On a peach of a wicket, a 167-run opening stand between new capture Matthew Scholefield (102) and Jack Earle (61) set up Mytholmroyd for a total of 300 for seven.
Ex-Royd player Steve Senior (84) and Rob Laycock (80) led the chase by putting on 166 for the second wicket and Richard Laycock (57 no) and Hasnain Wajid (46) helped complete the job.
Richard Laycock took 17 off the penultimate over bowled by Adie Gawthrope to leave seven more needed.
A single and four came off the first two balls off the final over, bowled by Jack Earle, but the next two produced only a bye.
With the scores level, Nigel Horsfall drove the penultimate delivery back to Earle, who might have run out Laycock.
Earle beat Horsfall’s bat with the final delivery and his brother Tom, wearing the keeping gloves, hit the stumps but Laycock had galloped home.
Both tails wagged at Warley where Queensbury made 220 for nine after being 138 for eight.
That looked likely to be enough when the hosts slumped to 126 for eight but James Whitworth (53 no) and Dan Syme (46) took Warley to the brink of victory.
Phil Sharples broke the stand in his sole over but last man Fraser Horsfall supported Whitworth, who collected the remaining seven runs required for victory.
Jer Lane, in third place, had to settle for nine points at home to Triangle, who gave an improved performance.
Michael Midwood fellow one run short of a century whilst fellow newcomer Adam Stocks made 86 not out in Triangle’s 261 for two.
Lane looked in trouble at 111 for six but experienced pair Jonny Lister (90 no) and Simon Collins (66 no) won it for the hosts with a stand of 154.
Oxenhope’s good start to the season floundered at home to Sowerby St Peter’s. They suffered at the hands of three players - Aiden Green (120), Hayden Bruce (119 no) and Chris Greenwood (six for 98) - as the visitors won by 54 runs .
Northowram HT are struggling for runs and suffered a third straight defeat after being dismissed for 100 runs in reply to SBCI’s 182 for nine.
Premier Division: Triangle 261-6 (Midwood 99, Stocks 86*, Silkstone 49*), *Jer Lane 265-6 (Lister 90*, Collins 66*, T Khan 43): pts 4-9. *Mytholmroyd 300-7 (Scholefield 102, J Earle 61), Booth 301-4 (Senior 84, Rob Laycock 80, Ric Laycock 57*, Wajid 46): pts 4-11. Sowerby St Peter’s 315-5 (Green 120, Bruce 119*), *Oxenhope 261-9 (Barker 61, Dyson 40, Greenwood 6-98): pts 11- 4.*SBCI 182-9, Northowram HT 100: pts 12-3.*Thornton 234-8 (G Soames 112, Carnall 70, Goulden 5-58), Copley 186-7 (Goulden 41*): pts 11-5. Queensbury 220-9, *Warley 223-9 (Atkinson 57, Whitworth 53*, Syme 46, Stewart 4-61): pts 5-11.
Points (after 3 matches): Thornton 35, Booth 34, Jer Lane 30, SBCI 28, Oxenhope 27, Sowerby SP 26, Copley 21, Mytholmroyd 18, Warley 18, Queensbury 12, Triangle 12, Northowram HT 7.
Sowerby Bridge lead Division One by eight points after Paul Gledhill’s 76 helped them win by three wickets at Shelf.
Second placed Cullingworth inflicted a first defeat of the season on hosts Southowram, winning by 102 runs.
Bridgeholme were bowled out for only 63 at Great Horton PC. Bobby Fielden scored 39 of them and six batsmen failed to trouble the scorer with Matthew Jordan (6-14) inflicting most of the damage.
Earlier, Chapel had posted 189 for five with Richard Hassell’s 70 turning out to be more than the visitors’ total.
Stones were restricted to 196 for four at Blackley and the hosts’ tight bowling was all important in a four wicket win.
First Division: Stones 196-4, *Blackley 197-6: pts 4-10. *Great Horton PC 189-5 (Hassell 70), Bridgeholme 63 (Jordan 6-14): pts 12-1. *Shelf 226-7 (Malik 67, Mellor 5-104), Sowerby Bridge 227-7 (Gledhill 76): pts 5-11. Cullingworth 277-3, *Southowram 175: pts 12-2.
Points (after 3 matches): Sowerby bridge 34, Cullingworth 28, Southowram 26, Blackley 26, Great Horton PC 17, Bridgeholme 17, Stones 16, Shelf 10.
Greetland made it rare back to back wins in Division Two with a two-wicket success over Luddenden Foot.
Sajid Ali (5-51) Hizar Hyatt (5-52) were the scourge of the visitors and contributions from a bevy of batsmen saw an uplifting victory.
Outlane lead the table after easily accounting for visitors Old Town.
Adil Shah hit 88 for the visitors but a total of 189 was inadequate and Chris Brook’s 92 not out sealed a seven wicket win.
Illingworth had much the better of their derby game at Bradshaw.
Batting first they powered to 286 for six after openers James Lawton (79) and Callum Cook(71) put on 137. Luke Brooksby put the icing on the cake with a swashbuckling 68 not out containing five sixes.
Jamie Moorhouse was instrumental in tying down the Bradshaw batters with one for 57 off 19 overs. The home side finished on 190 for five with Piers Fisher unbeaten on 54.
Clayton’s first ever visit to Leymoor brought 12 points despite the hosts looking as though they were finding their feet in the league.
An unbroken fifth-wicket partnership between Joseph Brown (59 no) and Tanweer Aslam (52 no) settled what had been an even game up to their arrival at the crease.
All 20 wickets fell at Mount, who beat Upper Hopton by 74 runs. Imran Ravat top scored with 71.
Birchencliffe were 77-run winners at home to Low Moor HT with Omar Latif’s 70 the top score.
Second Division: *Birchencliffe 247-8 (Latif 70, Ghori 44*, Stokes 4-58), Low Moor HT 170 (Osborne 49, Shah 4-53): pts 12-4. Illingworth St Mary’s 286-6 (Lawton 79, C Cook 71, Brooksby 68*), *Bradshaw 190-5 (Fisher 54*): pts 10-4. Luddenden Foot 142 (Ali 5-51, Hyatt 5-52), *Greetland 144-8: pts 4-12. *Leymoor 152 (Allison 45, Mistry 4-33, Aslam 4-42), Clayton 155-4 (Brown 59*, Aslam 52*): pts 3-12. *Mount 236 (Ravat 71, Ane Rawat 63, Iqbal 5-83), Upper Hopton 162 (France 42): pts 12-5. Old Town 189 (Shah 88), *Outlane 190-3 (Brook 92*): pts 3-12.
Points (after 3 matches): Outlane 36, Illingworth 34, Bradshaw 28, Clayton 26, Birchencliffe 26, Greetland 25, Mount 25, Upper Hopton 21, Low Moor 21, Luddenden Foot 13, Old Town 12, Leymoor 8.