Only 5.3 overs was possible in the first innings with the visitors reaching a strong position of 64 without loss before rain intervened and the players never returned to the field.
With no reserve day in scheduled, the rules of the tournament state that the team that ended higher on the league table will advance to the final.
The Warriors finished second in the standings, four points ahead of the third-placed Dolphins.
The team from Gqeberha will now travel to Paarl on Sunday to take on hosts Boland in the final of this season's CSA T20 Challenge.
The teams met at the same venue in the Qualifier 1 on Tuesday, with Boland beating the visitors by just five runs in a tense encounter that went down to the last over.
In the league phase of the competition, it was the Warriors that came out on top at St Georges' Park after compiling a massive total of 209-5 before bowling Boland out for just 111.
Tristan Stubbs says he is excited to have an opportunity to play and work on one format of the game as he eyes hitting prime form for the Proteas at the T20 World Cup early next year.
The Warriors got a second bite at the cherry when they won a super over to defeat the Boland Rocks by ten runs in the CSA T20 Challenge Final in sunbaked Paarl on Sunday.
The Dolphins remain in the hunt for the CSA T20 Challenge title after a 15-run victory against Western Province at Kingsmead on Wednesday.
Boland secured a place in the CSA T20 Challenge final after a tense five-run victory against the Warriors in the Qualifier at Boland Park on Tuesday evening.
