The Warriorz made 138-6 off their 20 overs after being put in to bat by the Capitals. Talia McGrath made 58* and captain Alyssa Healy made 36 against 3-26 off four overs from off-spinner Alice Capsey.
Meg Lanning (39), Capsey (34) and Marizanne Kapp (34*) then led a successful Delhi chase as the finalists needed just 17.5 overs to reach 142-5.
Pacer Shabnim Ismail took two wickets for the Warriorz.
With the league phase of the tournament now complete with all teams having played eight games, the Capitals, after finishing top-of-the-table with 12 points, are automatically into the final.
The Warriorz will have an opportunity to meet them there when they take on the Mumbai Indians, who finished as runners-up in the league phase, in the eliminator on Friday.
Earlier on Tuesday, Mumbai also finished the league phase with 12 points after a four-wicket win over the Royal Challengers Bangalore at the Sr DY Patil Sports Academy in Mumbai.
RCB made 125-9 from their 20 overs after losing the toss. Ellyse Perry and Richa Ghosh both made 29 for RCB as Amelia Kerr continued her good form with the ball with 3-22 from her four overs for Mumbai. Nat Sciver-Brunt and Issy Wong also took two wickets each.
Kerr then completed a fine all-round performance with an unbeaten 31 while Yastika Bhatia made 30 and Hayley Matthews 24 as the Indians reached 129-6 in 16.3 overs.
The eliminator will be held at the Dr DY Patil Sports Academy on Friday while the final will take place at the Brabourne Stadium on March 26.
Mumbai captain Harmanpreet Kaur led the way with an elegant 30-ball 51 to help her side post 162-8 off their 20 overs after the Giants won the toss and chose to field first.
Opener Yastika Bhatia also batted well for her 44 against Ashleigh Gardner’s 3-34 from four overs.
The Giants chase started in the worst way possible as English star Sophia Dunkley was dismissed by Sciver-Brunt with the first ball of the innings.
Harleen Deol and Sneh Rana both played fighting innings of 22 and 20, respectively, but the Giants chase never gathered momentum and saw them eventually be reduced to 107-9 off their 20 overs.
Sciver-Brunt ended her four over spell with 3-21 while Matthews took 3-23 off her four overs.
Scores: Mumbai Indians 162-8 off 20 overs (Harmanpreet Kaur 51, Yastika Bhatia 44, Nat Sciver-Brunt 36, Ashleigh Gardner 3-34) Gujarat Giants 107-9 off 20 overs (Harleen Deol 22, Sneh Rana 20, Nat Sciver-Brunt 3-21, Hayley Matthews 3-23, Amelia Kerr 2-18)
RCB made 155 all out off 18.4 overs after winning the toss and batting first. Wicket-Keeper Richa Ghosh scored 28 while captain Smriti Mandhana and Shreyanka Patil made 23, each for the Royal Challengers.
Matthews led the way with the ball for Mumbai with 3-28 from her four overs while Saika Ishaque and Amelia Kerr took two wickets, respectively.
The Indians, who made 207-5 in their first game against the Gujarat Giants, continued their excellent form with the bat by needing only 14.2 overs to reach 159-1 for their second straight win.
Matthews rounded out an exceptional all-round display with a top-score of 77 not out off 38 balls including 13 fours and a six. Sciver-Brunt provided excellent support with a 29-ball 55 invluding nine fours and a six.
Scores: Royal Challengers Bangalore 155 off 18.4 overs (Richa Ghosh 28, Smriti Mandhana 23, Shreyanka Patil 23, Hayley Matthews 3-28, Saika Ishaque 2-26, Amelia Kerr 2-30)
Mumbai Indians 159-1 off 14.2 overs (Hayley Matthews 77*, Nat Sciver-Brunt 55*, Yastika Bhatia 23).
The Capitals, who advanced to the final after finishing top-of-the-table in the league phase, made 131-9 off their 20 overs after winning the toss and batting first.
Captain Meg Lanning led the way with 35 while Shikha Pandey and Radha Yadav each made 27*.
Hayley Matthews was magnificent with the ball for Mumbai, picking up three wickets in her four overs while conceding only five runs. Issy Wong also continued her wicket-taking form with 3-42 from her spell.
The successful Mumbai chase took 19.3 overs and was anchored by Nat Sciver-Brunt, who finished not out on 60 off 55 balls including seven fours. Captain Harmanpreet Kaur made a 39-ball 37 in support as the Indians reached 134-3.
Sciver-Brunt was named player of the match while Matthews, who ended the season with 271 runs and 16 wickets, was named player of the tournament.
Her run total placed her fifth overall behind Lanning (345), Sciver-Brunt (332), Talia McGrath (302) and Kaur (281) while her 16 wickets were joint-most alongside Sophie Ecclestone.
