Paarl Royals only needed 154 to reach the inaugural showcase but Eathan Bosch claimed early breakthroughs before Adil Rashid, Anrich Nortje and Jimmy Neesham claimed two wickets each
Johannesburg: Pretoria Capitals 153-8, Paarl Royals 124 - Pretoria Capitals won by 29 runs
Pretoria Capitals eased into the inaugural SA20 final after defeating Paarl Royals at the Wanderers.
Rilee Rossouw returned to form with 56 from 41 balls to lead the charge.
Defending just 154, Eathan Bosch proved crucial with 2 for 17, dismissing Jason Roy (0) and Jos Buttler (13) early, a position Royals never recovered from.
Joburg Super Kings and Sunrisers Eastern Cape will contest the second semi-final on Thursday (February 9).
Rossouw put some poor form behind him (Sportzpics)
Capitals have been thoroughly dominant throughout the competition and despite losing to the Royals in the final group match were favourites to book their place in the final.
Batting first, Capitals slumped to 51 for 3 in the ninth over following the dismissal of Phil Salt (22), as Tabraiz Shamsi struck in successive overs.
That left the stage to Rossouw, who had endured a dismal tournament but found form at the perfect time.
The South African hit five fours and a trio of sixes to register his first SA20 half-century - brought up with the third of four fours in the 18th over off Lungi Ngidi.
He departed at the hands of Andile Phehlukwayo (3 for 29) but Bosch (22) cracked a six and four before two boundaries from Adil Rashid (8 not out) rescued the innings.
David Miller gave Royals late hope (Sportzpics)
Trouble brewed in the Royals' reply when Roy (0) was removed by Bosch, failing to reach double figures for the fifth time in the SA20.
Though there were brief moments of encouragement, a rebuild never truly materialised. Buttler became Bosch's second victim, Paul Stirling (21) was pinned lbw by Rashid, who then bowled Dane Vilas (18).
Batters making starts and failing to go on continued as Eoin Morgan (17) picked out Kusal Mendis, Evan Jones (0) was bowled by Jimmy Neesham, who later picked up Phehlukwayo (14).
Rain had forced a delayed start and it returned in the twilight of the chase, with Royals lagging behind the DLS target and required run rate.
Players remained on the field but it only allowed Capitals to secure victory, courtesy of a double wicket maiden from Anrich Nortje.