Joining them in the last four are Division III Walkovers, who pulled off the shock of the quarter-finals with victory over Abacus from the top flight.
Completing the line up are St Ouen and Jersey Academicals.
Carlyon carried his bat, completing his half-century in the 11th of the 15 overs before accelerating over the last four overs to bring up his century off the penultimate ball of the innings.
He was particularly harsh on John Douglas.
The Beeches bowler’s opening two-over spell earned him a wicket at the cost of just four runs, but when he returned to bowl his last Carlyon spoilt his figures as he hit three consecutive sixes in an over costing 27 runs.
Jason Carpenter (20) was the next highest scorer as Sporting Club closed on an impressive 168 for 6.
Dave Buxton carried his bat for 51 in the Beeches innings but only Jim Walls (44) offered meaningful support in the face of accurate bowling from Nick Jewell and Mark Reynolds, in particular.
Beeches ran out of time on 143 for 7 – 25 runs short.
Sporting Club will meet St Ouen in the semi-final.
The westerners posted a sizeable 170 for 5 at FB1 against Air Conditioning.
Rob Tewkesbury (67) and Ward Jenner (47) were the main contributors to the total.
Mark Saralis (28), Ian Crocker (40), Tom Minty (28) and Dan Archer (24) all got starts for Air Conditioning but they eventually ran out of overs to finish on 139 for 7, 31 runs short.
Walkovers only formed in 2000 and a delighted club president John Patterson said: ‘This is the biggest scalp so far – the first time we have beaten a Division I side and the first time we have reached the semi-final of the JEP KO Cup.
‘Our fielding was the key.
We were energetic and it helped to keep their runs down.
‘Then everyone contributed with the bat.
It didn’t look good when we were five down for about 70 runs, but we sensed the panic as Abacus started moving their field around and that made us think we were in the game.’ Walkovers eventually reached their target off the fourth ball of the 15th over to set up a semi-final against Jersey Academicals of Division II.
Academicals defeated JUBRFC by eight wickets on FB3.
John Breeze (72 not out) and Alan Blair (20 not out) batted well for JUBRFC who totalled 131 for 3.
Ryan Driver, who had earlier taken 3 for 12 in his bowling spell, hit an unbeaten 92 to guide Academicals to victory.
l JEP KO Cup semi-finals, Tuesday 21 june, SCF v St Ouen (FB1); Walkovers v Jersey Academicals (FB2).